Develop Bugs

How to best go about backing up stock/installing a custom ROM

Hi,
After doing some reading on here I am a little unsure on the best way to back up my HTC One M9 (GSM) stock recovery/system. My software number is 3.50.710.1 (Android 6.0) and it came from Optus (Australia). I cannot seem to find an RUU file for this firmware anywhere online; only earlier versions are available. My understanding of this is that I need an RUU file for my specific firmware as a fail-safe in case I mess something up and need to return to stock?
My questions are:
1) Can I get my phone back to the current complete stock firmware and be able to receive future OTA updates without turning s-off and without copying anything from my phone before I flash TWRP and a custom ROM?
2) If not is there anyway that I can back up my phone it its current stock state that will allow me to go back to this state if I want to go back to my stock Optus firmware or to install OTA updates? (Including the stock radio/recovery)
3) Reading this post as well as others leads me to believe that I may stop my mobile radio working by flashing a custom ROM (especially as the linked post has the exact same firmware as me). How can I avoid this, or fix it if it happens to everyone?
I am ideally looking for a custom ROM which improves over the stock firmware. My priority is maximum battery life, with customisation and HTC 10 system UI/apps a secondary focus. Any recommendations would be great, as well as tweaks and kernels which help give the maximum battery life.
Cheers!

You can't backup your firmware (and that includes your radio). However if you read my google sheet you'll find instructions for backing up your current boot.img, your system and the stock recovery. If you do it correctly those files will suffice for recovering the ability of installing OTAs. No personal data will be backed up so maybe you want to share your backup with us afterwards.
There is a custom kernel for CM/AOSP roms which is said to repair the signal problems. As far as I read some sense rom users reported that flashing the stock boot.img recovered their signal. However this doesn't seem to work for every user. So you'll need to try by yourself.

Flippy498 said:
You can't backup your firmware (and that includes your radio). However if you read my google sheet you'll find instructions for backing up your current boot.img, your system and the stock recovery. If you do it correctly those files will suffice for recovering the ability of installing OTAs. No personal data will be backed up so maybe you want to share your backup with us afterwards.
Click to expand...
Click to collapse
Thank you so much! I have managed to find the guide you mentioned to backup the stock boot image, system image and recovery. By the looks of it the tab to the right is the guide to return my phone to its original state, which is good. I'm more than happy to share the backup once I do it.
Flippy498 said:
There is a custom kernel for CM/AOSP roms which is said to repair the signal problems. As far as I read some sense rom users reported that flashing the stock boot.img recovered their signal. However this doesn't seem to work for every user. So you'll need to try by yourself.
Click to expand...
Click to collapse
Okay, well I am planning on keeping s-on at this stage, so I'm left with Sense based ROMs I believe? I have read that LeeDroid is the best for battery life, does this sound right? If so I am unsure if I can flash it as it says "Please make sure you have the latest HTC Hima 3.35.XXX.XX Marshmallow firmware installed prior to installing this ROM" because my software number is 3.50.710.1?
Thanks again!

Da Doom Lord said:
Okay, well I am planning on keeping s-on at this stage, so I'm left with Sense based ROMs I believe? I have read that LeeDroid is the best for battery life, does this sound right? If so I am unsure if I can flash it as it says "Please make sure you have the latest HTC Hima 3.35.XXX.XX Marshmallow firmware installed prior to installing this ROM" because my software number is 3.50.710.1?
Click to expand...
Click to collapse
I've read that several times in the near past and I actually don't understand it. You never needed S-OFF for flashing none-sense based roms as long as I started using Android/HTC phones and that was back in 2012. Why do so many people think they need S-OFF for AOSP?
I personally prefer the Viper rom. But taste differs and in the end the best advice I can give is try it out by yourself. Everyone has different needs and is using his/her phone in a different way. The best rom for person a might be an awful choice for person b since he/she has completely different needs.
I can't tell you whether you can use Leedroid. Test it and report back. That's how xda works. You might be able to use it after you flashed your stock boot.img but I don't know whether you really are or not. The warning is written so that people don't start flashing that rom with a lower firmware version. On older HTC phones flashing an "older" rom has never been an issue on newer firmware versions whereas flashing a newer rom on an older firmware never goes well (even on the M9). However many things have changed since the M9. There is no hboot anymore, the Download Mode got introduced, google changed the way OTAs are checking whether your system is modified, and so on. (Just to mention a few changes.) Those issues with the lost signal didn't even exist on pre-3.x firmware versions of the M9. Therefore users like you who use a not so common firmware (in comparison to the user numbers of the most common firmware bases: international, taiwanese and the developer firmware) have no other choice but trying out by themselves or getting S-OFF and changing to a more common firmware.

Flippy498 said:
I can't tell you whether you can use Leedroid. Test it and report back. That's how xda works. You might be able to use it after you flashed your stock boot.img but I don't know whether you really are or not. The warning is written so that people don't start flashing that rom with a lower firmware version. On older HTC phones flashing an "older" rom has never been an issue on newer firmware versions whereas flashing a newer rom on an older firmware never goes well (even on the M9).
Click to expand...
Click to collapse
I have followed your guide and now have the latest stable LeeDroid ROM installed and TWRP. Just as I predicted the radio was not originally working. When I restored my stock boot.img from the original backup I performed it began to work. Thanks so much for your help! I'll upload the backup to cloud storage when I get access to a decent internet connection and then I'll share it to help others out.

Verizon to US Unlocked Questions

I've been reading around and mostly want to know everything for this for that time when CM becomes stable.
Anyways:
Do you lose Verizon network functionality? By this I really mean, calls, SMS, SMS, voice mail, and 4G LTE.
When converted...just act like it's the US unlocked model when flashing ROMs? Do I need to flash the Verizon radio?
I'm confused...and the final question..
To convert it requires a SuperCID and then RUU flash, right? I've seen Sprint owners do it and one Verizon owner, but the instructions were all very unclear to me.
Thanks!
Answers are on post #4, tested it out after being sure of how to do this. If you're lazy, click here...

I've converted my VZW branded 10 to U.S Unlocked. I am NOT using the phone on Verizon network, so I can only answer part of your questions.
To convert, I changed my cid to SuperCID (22222222) and flashed the latest stock RUU.exe from HTC.com for U.S Unlocked. Pretty simple.
I can't tell you if the phone would work on Verizon network, but I would assume it would with a radio flash to get the basic things you mentioned working, as outlined in:
http://forum.xda-developers.com/verizon-htc-10/how-to/vzw-how-to-unlocked-model-vzw-t3376743
Haven't yet flashed any non-stock roms, but I can't imagine why this would be a problem. Also the CM thread has some people who flashed the Unlocked firmware on a VZW phone and got CM working.

I haven't and probably will never try, but I see advanced feature breaking after you do this like wifi calling and the like. but ive also heard all that's different is the radio. but theres different settings unlocked and hidden between the two that may give issues also.
so just give it a shot if you really want. the worst that would happen is you would need to switch back to Verizon firmware.

Tested it out...
Tarima said:
I've converted my VZW branded 10 to U.S Unlocked. I am NOT using the phone on Verizon network, so I can only answer part of your questions.
To convert, I changed my cid to SuperCID (22222222) and flashed the latest stock RUU.exe from HTC.com for U.S Unlocked. Pretty simple.
I can't tell you if the phone would work on Verizon network, but I would assume it would with a radio flash to get the basic things you mentioned working, as outlined in:
http://forum.xda-developers.com/verizon-htc-10/how-to/vzw-how-to-unlocked-model-vzw-t3376743
Haven't yet flashed any non-stock roms, but I can't imagine why this would be a problem. Also the CM thread has some people who flashed the Unlocked firmware on a VZW phone and got CM working.
Click to expand...
Click to collapse
afuller42 said:
I haven't and probably will never try, but I see advanced feature breaking after you do this like wifi calling and the like. but ive also heard all that's different is the radio. but theres different settings unlocked and hidden between the two that may give issues also.
so just give it a shot if you really want. the worst that would happen is you would need to switch back to Verizon firmware.
Click to expand...
Click to collapse
Changed my CID to SuperCID (22222222).
Got the latest Unlocked U.S. FW from the HTC Dev site (RUU EXE) and flashed it.
Flashed a Verizon radio in fastboot. (The same one used to make the actual U.S. Unlocked variant work on Verizon)
Flashed TWRP in fastboot.
Formatted my data.
It booted without issue.
Followed this guide (though, on initial boot it showed 4GLTE active BUT no bars (line through them).
After following the guide, I rebooted.
Testing functions:
Calls: Functional and no delays.
SMS: Functional and fast.
MMS: Functional and fast.
Data connection: Functional.
Behavior after reboot: Starts again with the bars crossed off, eventually comes up and working though. Works after that, calls too. Takes about 45 seconds to connect.
Thing to note: It seems as if my signal strength is lessened. Though, this could easily be placebo, weather, etc. It's 1:31AM and I've never paid attention to it before.
Network comes up as 3107 instead of Verizon Wireless.
HTC software updates seem to be broken, it gives a corrupted error. I'm locked/S-OFF, so dunno.
Final deduction: It seems to functional and all, without hiccup most likely. It takes longer to connect than the stock VZW FW does of course, but after the boot it seems fine.
I'm done testing this for now, but if anyone is wondering yeah go for a it. It seems to be fine besides a slower initial connection. Excited for CM to become stable, then I'll play with this some more.

Ariac Konrel said:
Changed my CID to SuperCID (22222222).
Got the latest Unlocked U.S. FW from the HTC Dev site (RUU EXE) and flashed it.
Flashed a Verizon radio in fastboot. (The same one used to make the actual U.S. Unlocked variant work on Verizon)
Flashed TWRP in fastboot.
Formatted my data.
It booted without issue.
Followed this guide (though, on initial boot it showed 4GLTE active BUT no bars (line through them).
After following the guide, I rebooted.
Testing functions:
Calls: Functional and no delays.
SMS: Functional and fast.
MMS: Functional and fast.
Data connection: Functional.
Behavior after reboot: Starts again with the bars crossed off, eventually comes up and working though. Works after that, calls too. Takes about 45 seconds to connect.
Thing to note: It seems as if my signal strength is lessened. Though, this could easily be placebo, weather, etc. It's 1:31AM and I've never paid attention to it before.
Network comes up as 3107 instead of Verizon Wireless.
HTC software updates seem to be broken, it gives a corrupted error. I'm locked/S-OFF, so dunno.
Final deduction: It seems to functional and all, without hiccup most likely. It takes longer to connect than the stock VZW FW does of course, but after the boot it seems fine.
I'm done testing this for now, but if anyone is wondering yeah go for a it. It seems to be fine besides a slower initial connection. Excited for CM to become stable, then I'll play with this some more.
Click to expand...
Click to collapse
I was the guinea pig for this in regards to Sprint, but you've seem to partially answer a question I had.
I know that the Verizon and US Unlocked use the same model ID, but the Sprint and internal do not. Leaves me wondering if I could just run the RUU for my Sprint phone.

Ariac Konrel said:
Changed my CID to SuperCID (22222222).
Got the latest Unlocked U.S. FW from the HTC Dev site (RUU EXE) and flashed it.
Flashed a Verizon radio in fastboot. (The same one used to make the actual U.S. Unlocked variant work on Verizon)
Flashed TWRP in fastboot.
Formatted my data.
It booted without issue.
Followed this guide (though, on initial boot it showed 4GLTE active BUT no bars (line through them).
After following the guide, I rebooted.
Testing functions:
Calls: Functional and no delays.
SMS: Functional and fast.
MMS: Functional and fast.
Data connection: Functional.
Behavior after reboot: Starts again with the bars crossed off, eventually comes up and working though. Works after that, calls too. Takes about 45 seconds to connect.
Thing to note: It seems as if my signal strength is lessened. Though, this could easily be placebo, weather, etc. It's 1:31AM and I've never paid attention to it before.
Network comes up as 3107 instead of Verizon Wireless.
HTC software updates seem to be broken, it gives a corrupted error. I'm locked/S-OFF, so dunno.
Final deduction: It seems to functional and all, without hiccup most likely. It takes longer to connect than the stock VZW FW does of course, but after the boot it seems fine.
I'm done testing this for now, but if anyone is wondering yeah go for a it. It seems to be fine besides a slower initial connection. Excited for CM to become stable, then I'll play with this some more.
Click to expand...
Click to collapse
Does your volte work ? Something you can try is flash Viper10 and select as a verizon model instead of the unlocked version, this will add get you on global mode and I think will fix your signal issues. You list your on Viper10 just dirty flash it again selecting verizon version and give it a try. If it does not help you can always just dirty flash again and go back selecting the unlocked version. Just do a back up before doing this and you will covered if you just want to restore the back up. From my experience this might help just do not try running a custom kernel for the verizon version if you converted to the unlocked as your camera may not work and keep forcing close but you can run a custom kernel for the unlocked if you converted to unlocked. My recommendation would be to run the Elite kernel as I have had really good luck with the Elite kernel on the Htc 10 and I think theirs is what I run well on my Motorola nexus 6 also.

Ariac, regarding OTA software updates on the phone, I think you get that "corrupt" message because you flashed a different radio and twrp. Might be worth flashing the original Unlocked radio/recovery back and see if it at least detects the latest update. If it does, you'll also need to remove superCID to be able to take the update.
I reflashed the RUU yesterday, removed superCID and I was able to take the OTA.

Converted dev phone, reception with 4.14.617.6 but not after OTA to 4.19.617.1

Hello,
After some troubles I've converted my S-OFF x.xx.410.xx phone to a dev edition 2 weeks ago by reading a lot on this forum. I believe I did the following:
- flash 0PJAIMG nougat.zip from bootloader mode / SD
- run 4.14.617.6 RUU after flash
This worked for perfectly for a time.
On 1-1-2017 I got the 4.19.617.1 OTA notification which I accepted as I did not modify the system in any way. OTA completed succesfully however after OTA the phone lost mobile reception. In Android IMEI was not visible. In fastboot I saw IMEI with "fastboot getvar all".
Re-flashing RUU 4.14.617.6 worked to regain mobile reception however OTA nofication would of course still appear. Today I retried but with the same results -- no mobile reception after OTA.
To confirm with the new RUU available I ran the 4.19.617.1 RUU to re-flash phone and indeed no signal at all.
Then I ran the 4.14.617.6 RUU and signal again.
I read this in the FAQ:
"Q1: Everytime I flash a custom rom I lose my IMEI, my mobile reception and my phone stops recognizing my sim card. What's the reason for this?
A: You probably flashed a custom rom that is based on firmware 3.35.x although the firmware of your phone is 3.y (with y being any other number than 35). The boot image of 3.35.x based roms is not compatible with your firmware version. The solution of the problem depends on the question whether you are trying to install a Sense-based rom (like ICE or ViperOneM9) or a non-Sense-based rom (like CM): For Sense-based roms you just need to re-flash the stock boot image of your current firmware version."
This seems like my problem except I run RUU directly from HTC. Any idea on what I can do to accept OTA / reflash phone with 4.19.617.1 RUU ?
Thank you!

Was the phone rooted at the time of accepting the ota?.
There is a thread somewhere that explains how to fix the no signal issue on nougat dev edition.
I don't see the point in risking a brick for a beta firmware (dev edition is the beta to carrier versions) which is not necessarily a better firmware.
Also, make sure the rom and firmware you flash IS GSM and NOT CDMA.
Beamed in by telepathy.

@Fritti: The error that is described in the FAQ only appears if you flash a custom rom while using an incompatible firmware. You've used a RUU and are using the stock rom that got flashed by the RUU. That means firmware and rom are matching. Unfortunately, that means that I have no clue why you're facing this issue. There's no reason why you should lose your reception since all GSM versions are more or less the same if you compare their hardware. As far as I know only the LTE bands of the GSM versions differ.
shivadow said:
Was the phone rooted at the time of accepting the ota?.
There is a thread somewhere that explains how to fix the no signal issue on nougat dev edition.
I don't see the point in risking a brick for a beta firmware (dev edition is the beta to carrier versions) which is not necessarily a better firmware.
Also, make sure the rom and firmware you flash IS GSM and NOT CDMA.
Beamed in by telepathy.
Click to expand...
Click to collapse
If the phone was rooted the OTA wouldn't have been installable.
And please stop posting things that aren't true. The dev firmware is not a beta version. It's the US equivalent of the European 401 firmware or the Asian 708, 709 or 710 firmware. Beta firmwares look like this one: 2.10.401.180. They have three numbers behind the last dot. If you compare the 3.x firmware of SKU 401 and 617 you'll notice that 3.35.401.12 and 3.35.617.12 are almost exactly the same except for some contintent-specific tweaks.
It is true that the dev edition is not necessarily better than the 401 one. However, it's up to every single user to choose whether he or she wants to wait until the latest update gets released for his/her SKU or whether they want to convert to the dev edition which receives all updates first (in case of the M9).

Flippy498 said:
@Fritti: The error that is described in the FAQ only appears if you flash a custom rom while using an incompatible firmware. You're used a RUU and are using the stock rom that got flashed by the RUU. That means firmware and rom are matching.
Click to expand...
Click to collapse
Yes, that's what I thought.
Unfortunately, that means that I have no clue why you're facing this issue. There's no reason why you should lose your reception since all GSM versions are more or less the same if you compare their hardware. As far as I know only the LTE bands of the GSM versions differ.
Click to expand...
Click to collapse
Exactly. I don't understand either. Something get's flashed by the 4.19 RUU that messes up the IMEI detection? Is it possible to extract system.img from 4.19 RUU and just flash that to check whether that works?
If the phone was rooted the OTA wouldn't have been installable.
Click to expand...
Click to collapse
Indeed, phone was not rooted. I used 4.14 RUU and then no other flashes/mods.
And to be clear, for now it seems that I can repeat this -- run 4.19 RUU and no signal, run 4.14 RUU and signal again. If there is some radio partition and/or radio data partition that I can dump to check hex diffs I could try.

Fritti said:
Yes, that's what I thought.
Exactly. I don't understand either. Something get's flashed by the 4.19 RUU that messes up the IMEI detection? Is it possible to extract system.img from 4.19 RUU and just flash that to check whether that works?
Indeed, phone was not rooted. I used 4.14 RUU and then no other flashes/mods.
And to be clear, for now it seems that I can repeat this -- run 4.19 RUU and no signal, run 4.14 RUU and signal again. If there is some radio partition and/or radio data partition that I can dump to check hex diffs I could try.
Click to expand...
Click to collapse
You could use the decryption tool that is linked in the readme thread for extracting the system image and the firmware files.

Hi,
I'm facing the same issue - I think. I'm currently using a 4.14 original RUU ROM from HTC without modification.
When I accept the 4.19 OTA I lose connectivity in a most peculiar way: there are still signal bars and the phone confirms a LTE connection.
But there are no more APN options and no data. Also when I place a call the phone claims I'm out of service area.
One other thing I noticed is that the dialer shows a different number format when entering a phone number. With 4.14 I have the normal DUtch standard for dashes and area codes. With 4.19 I have a US standard. Could it be that the phone thinks I'm in the US and would a edit to the build.prop help?
I hope someone has some advice.

Gawain1986 said:
Hi,
I'm facing the same issue - I think. I'm currently using a 4.14 original RUU ROM from HTC without modification.
When I accept the 4.19 OTA I lose connectivity in a most peculiar way: there are still signal bars and the phone confirms a LTE connection.
But there are no more APN options and no data. Also when I place a call the phone claims I'm out of service area.
One other thing I noticed is that the dialer shows a different number format when entering a phone number. With 4.14 I have the normal DUtch standard for dashes and area codes. With 4.19 I have a US standard. Could it be that the phone thinks I'm in the US and would a edit to the build.prop help?
I hope someone has some advice.
Click to expand...
Click to collapse
Yes, that sounds like the same issue. You can actually edit the settings in the phone to disable the US international prefix. However it does not help for the out of service issue.
I have not yet had the time to try and flash only the firmware / recovery / system from 4.19, I will report back once I have tried.

Fritti said:
Yes, that sounds like the same issue. You can actually edit the settings in the phone to disable the US international prefix. However it does not help for the out of service issue.
I have not yet had the time to try and flash only the firmware / recovery / system from 4.19, I will report back once I have tried.
Click to expand...
Click to collapse
I have some news. I took the 4.19 No-Wipe firmware and flashed it by putting it on my SD card as 0PJAIMG.zip. It flashed and now I'm working on the 4.14 ROM with 4.19 firmware. All is working wel, most notibly making calls and using data.
This leads me to believe there is something in the Kernel/ROM of 4.19 that breaks our calling and data.
Does anybody have any other ideas to make 4.19 work?

The plot thickens .
I installed ICE ROM 4.19 after flashing firmware 4.19 and I had the same problem back, out of service area.
So I started comparing the build.prop files in the 4.14 ROM from HTC and the 4.19 ICE ROM. Then I changes a few lines to these values and I was able to call:
ro.ril.hsxpa=4
ro.ril.hsdpa.category=14
ro.ril.hsupa.category=6
ro.aa.rid=115
To get data (and be able to log in to a google account) I did another thing. I used the dialer to call *#*#4636#*#* and set the phone to WCDMA preferred and I had data.
The only thing left is to be able to use LTE/4G but that's for another time, I can finally use my phone on this firmware!

Gawain1986 said:
The plot thickens .
I used the dialer to call *#*#4636#*#* and set the phone to WCDMA preferred and I had data.
The only thing left is to be able to use LTE/4G but that's for another time, I can finally use my phone on this firmware!
Click to expand...
Click to collapse
Now try switching it back to LTE/WCDMA/GSM.
I had the same with S.Rom and after getting it to connect the way you did, switching back to auto gave me 4G again

bonesy said:
Now try switching it back to LTE/WCDMA/GSM.
I had the same with S.Rom and after getting it to connect the way you did, switching back to auto gave me 4G again
Click to expand...
Click to collapse
No such luck for me... As soon as my phone sees LTE, the phone force closes and aftter I have no Data and I'm out of service area again.

So I know this is nearly a necro but I wanted to give an update that I cannot try this anymore -- shortly after the failures started my phone got stuck in a bootloop. This had to be hardware error as it simply started one morning while I did not change anything. The Vodafone shop I brought it to agreed and send my unit in for (warranty!) repairs. I've since got it back with Android 7.0 on version 4.28.401.3, so there is no need for me to switch to dev edition now. I cannot say whether the signal issues were a symptom or a cause for my unit to fail.
Hoping that Gawain1986 has fixed his issues as well!

Strange signal/network behavior

hi!!
I have a HTC M8 dual sim, with a custom 7.1.2 ROM; I have not upgrade or install any other radio file than the stock.
It happens that when I get far away from my city, i lost all my signal. and in general it doesn't come back until I reboot the device (a soft restart works). and then I get signal again, but only for several minutes; then it all repeats.
from time to time it gets signal and stays like that, so I suspect that my device is not been able to get signal for the other operators of my country (here the cells are shared between the operators.. and I suppose that it works that way worldwide).
this is pretty annoying because I love to travel, and virtually do it without phone capability.
could it be that I have upgraded my phone that far from stock that the radio firmware got obsolete? or it may be a hardware problem?
tthanks ^^

xxopiumxx said:
could it be that I have upgraded my phone that far from stock that the radio firmware got obsolete? or it may be a hardware problem?
Click to expand...
Click to collapse
I don't know what you mean that the radio "got obsolete". Receptions issues may be possible with a custom ROM (which ROM?). But it's impossible to say whether the ROM is the issue or not, unless you go back to the stock ROM, and see if the problem persists.

redpoint73 said:
I don't know what you mean that the radio "got obsolete". Receptions issues may be possible with a custom ROM (which ROM?). But it's impossible to say whether the ROM is the issue or not, unless you go back to the stock ROM, and see if the problem persists.
Click to expand...
Click to collapse
I meant that the part of the hardware firmware that manage the modem, may be too outdated respect of the rom . i am just taking a guest.
until yesterday i was runing Lineage OS 14.1; but it had a horrible issue that after a call it kept in "hanging" until I restarted. so, i went back to CM13.

xxopiumxx said:
I meant that the part of the hardware firmware that manage the modem, may be too outdated respect of the rom . i am just taking a guest.
Click to expand...
Click to collapse
The firmware is stuck on Marshmallow, since HTC doesn't support this phone with updates anymore. All the ROMs will work with Marshmallow firmware, since there is no other firmware for it to work with for this device.

redpoint73 said:
The firmware is stuck on Marshmallow, since HTC doesn't support this phone with updates anymore. All the ROMs will work with Marshmallow firmware, since there is no other firmware for it to work with for this device.
Click to expand...
Click to collapse
good. so i wanted to know if this that you tell me could cause something like the mentioned issue; or if i should be looking into hardware ones.

xxopiumxx said:
good. so i wanted to know if this that you tell me could cause something like the mentioned issue; or if i should be looking into hardware ones.
Click to expand...
Click to collapse
Back to stock is probably your best bet, and see if the problem persists. Really not much else you can do, especially since I think Lineage or CM are the only custom ROMs for the dual sim?
If you do back to stock, and still have problem, it may be a hardware issue. Might be a network issue, as well.

Why can't you update PRL and profile in Lineage and other customs - and can we fix it

So as I've looked into it, it appears that nothing has changed here in the 2-3 years since I last explored this issue. I'm talking about the fact that you can't successfully update PRL and profile on CDMA carriers in LOS and AOSP ROMS. The usual behavior if you even have the option in the UX is that you get a force close. I'd love to understand why this hasn't been addressed.. It's a huge reason someone would stay on stock over AOSP/LOS. I saw someone suggesting a Nexus 5 dev had some success using a couple of APKs including OmaDmclient.apk, and a few threads here and on Reddit talking about how it must've been broken by an AOSP contributor, but in any event it still doesn't work. Isn't this something that the LOS team could fix if they wanted to?

The issue with CDMA is that most of the stuff isn't open source. This is why the aosp source code is targeted to GSM. So I sought this will get fixed any time soon.

Same problem... I think
My neighborhood has excellent Sprint 4G LTE coverage and it's much faster than T-Mobile. I happen to use Ting (which allows you to choose between T-Mobile GSM and Sprint CDMA, although to switch from one to the other costs $20). GSM isn't really an option for me.
Anyway, I used to have this problem with my LG Volt LS740. I could work around it by forcing a PRL and profile update on stock and then flashing to Cyanogenmod.
That phone finally bit the dust. I have now inherited my wife's Moto G 2015 (osprey) XT1548. Really nice phone.... but the issue is, the latest stock I can find is Android 6.0. I can activate the phone and get great 4G LTE on stock, but to flash to Lineage OS 14.1 (or AOSP) I have to wipe the device. I simply can't get it to pick up the 4G LTE service on the custom ROM's (tried both). This is a real problem.
As I understand it (admittedly from reading Wikipedia), the PRL contains an "acquisition table" that prescribes the frequencies/modes that the device will communicate on... so I think that's probably my issue. After doing the prescribed wipes in the ROM installation documentation, flashing the ROM, and booting the device, I think I've lost the PRL somewhere in that process.
Is there some way to retrieve the PRL while the device is on stock and put it back when flashing custom? If the PRL is indeed stored on the R-UIM, should I just remove the R-UIM during the first boot? Maybe I'm wrong and the problem isn't really the PRL.
Any thoughts? Please don't tell me to switch to GSM. The GSM coverage here is just plain bad from both carriers who offer it in my neck of the woods.

I have this same exact question. Ting, N910P note 4 that was originally Sprint, and days-old Lineage 16 / Andorid 9.0 . The latest stock rom is 6.0.1, and works fine. Lineage 16 works 99% fine and I'd really rather use that. But LTE doesn't work. If I force it to use 3G only, it actually all works. data, voice, text, bluetooth, gps… and being Lineage, I don't have to try to surgically remove all the spyware and other crapware without breaking it. It's just not in there in the first place. I'd really rather use that.
I would be fine having to extract things from the stock rom and edit files or whatever if it were at least just known what needed to be done. I'm fine with the fact that Lineage nor anyone else can actually include and redistribute any carrier proprietary stuff.

it should be possible
Has anyone figured this out?
I too have devices on ting, fantastically built devices that run amazingly thanks to a solid construction, the support of many many developers who are craft some of the best ROMs for any device I've ever seen, considering the limited specs of the XT1031s. Fortunately/adequately enough though, they only run on 3G Sprint, Boost originally, moved to Ting for their great rates for FreedomPop customers when they bought them out.
Anyway, currently to get a device on ting, I have to flash the latest 5.1 official stock Boost Mobile Rom with the latest radio baseband and firmware and such. A process thats pretty involved. I'm hoping that I can backup the stock image using TWRP, as when I went through the process of reloading the official image through the individual files via mfastboot, I skipped the logo and recovery files, and since I was able to retain my custom logos for boot and bootloaderunlocked screens, and the recovery, I'm hoping to be able to make an image of the stock ROM, which if at all possible, I'm going to do my best to make as bare bones as possible. May start with flashing the bloatware removed version of stock thats available, then going through and removing basically every app on the phone with the exception of settings and anything to do with phone, phone/carrier services, sim toolkit, etc, so I can have the smallest image possible that could maybe be restored everytime/anytime that I want to update the PRL or Profile. Which it looks like theres a new version of each released at a minimum every 3 months, as I just activated another device this way and there was only an incremental update of the last digit. If this works, great. If it doesn't then I hope that theres an answer to the question in the initial post of this thread;
Is there a way to update the CDMA PRL and Profile on a device that is running a custom ROM? If so, is it something the ROM needs to specifically support or is it something that is possible to do with a bundle of apks? Like sim toolkit and the like?
If its ROM related, are there, or would it be possible to take the necessary components from the stock files and install them in Xposed or Magisk? Or perhaps the buttons in the settings panel of the stock rom simply executes a series of commands that can be executed within a terminal CLI on the custom ROM? I assume that since the custom ROM clearly has access to the 3G radio since I can make and recieve calls, I have data, and text messaging (haven't tried MMS, but I assume it works) so why couldn't it do one more thing and initiate the PRL update?
I assume that even the stock rom doesn't ever touch the PRL or Profile, seeing as they remain even after a user data wipe, and are available for the radio to continue to use with custom roms, which means that the radio chip has to be the one storing the PRL Profile, so I bet that the radio also directly downloads those files from the carrier when asked to do so, and the stock rom must only come into play for the base logicstics of it all such as radio-"is this prl/profile a newer version than the one that i have now?" and phone-"yes, download new, purge old, flash new, tell me when done and leave me alone" Since the radio doesn't have its own processor for those sorts of things perhaps? If thats the case, then that should imply that theres nothing particularly proprietary or licensed, etc, that a rom would explicitly need to have in order to initiate these updates since it would never directly need to touch/see the files, just know that they were updated and what version number they are. What also lends me to believe this is the case is the fact that you can't select to downgrade the prl/profile, rollback, or load one manually, at least not that I can see.
So basically I'm saying that I hope it should be something simple to do. And if it is simple to do, you would think that custom roms would be able to read the carrier correctly too? Right now my new device reads "Boost" still. My previous one when I got it on ting I wanna say actually read ting afterwards. But when I loaded ressurrection remix, I had no cell/data/voice nothing, It just kept asking me for a sim card, which this phone doesnt have at all. When I loaded Lineage, everything cell related work. But can't update prl/profile, and carrier reads as "3G Roming Indicator Off" Which idk why thats the case.
Perhaps I'm missing something
Perhaps custom roms are missing a few somethings.
The only sure thing is that carriers need to just not be so greedy/dumb/uselessly difficult, and make giving them money for service easier, preferably without questions. Or at the very least actually provide some security so all this nonsense is at least worth something in the end to the end user, instead of being done so that they can try to spy on your unencrytped texts and calls to sell to advertisers, and selling access to the higest bidders such as the government and bounty hunters, whilst preventing you from restricting that information.