Develop Bugs

[Q] losing wifi connectivity- full bars but all gray

so, I've read around here on the XDA forum about problems with wifi connectivity where we have full bars for wifi but they are gray and you are not getting out. many describe my situation but I've not seen any real solutions...
my problem is that I can connect to my wifi router without issue but then a random amount of time later, sometimes fairly quickly and sometimes it's hours later, I will pick up the phone and see full bars but they are gray and I'm not getting out. I can try opening a terminal window and pinging the gateway/dns servers and can't even reach the gateway.
things I have tried:
- turned off MAC filtering on the wifi AP
- switched from a 5 GHZ wifi on the AP to 2.4 GHZ net on the AP and vice versa
- manually set the phone wifi preference to one or the other (5 or 2.4)
- battery pull on the phone
- delete network settings for my AP and reconfigure
I have not yet tried a static IP config on the phone but I can easily try that... {edited to add} well, I tried static config and that didn't help at all...
one other tidbit of info, I have a work Blackberry with wifi and it never loses wifi connectivity so this is a problem unique to my Nexus.
I'm running Cyanogen 10.0.0-toro and no, I haven't tried a full wipe and reload yet.
thoughts or suggestions?

I'm not trying to threadjack here, but I just wanted to share my experiences.
I've been have the exact same thing happen to my phone (Nexus maguro). I've tried every JB rom I could find, several different kernels and my wifi eventually always goes grey on me. All network activities stop. I'm back on stock everything right now and it still happens.
It happens on my home wifi as well as work wifi.
I'm about to puttstock ICS on my phone and try that out for a couple days.
Anyway, good luck with your problems, i'm going to follow this thread in hopes you'll get a solution that may help me.
If I do figure anything out i'll post back.

jrmacarthur said:
I'm not trying to threadjack here, but I just wanted to share my experiences.
I've been have the exact same thing happen to my phone (Nexus maguro). I've tried every JB rom I could find, several different kernels and my wifi eventually always goes grey on me. All network activities stop. I'm back on stock everything right now and it still happens.
It happens on my home wifi as well as work wifi.
I'm about to puttstock ICS on my phone and try that out for a couple days.
Anyway, good luck with your problems, i'm going to follow this thread in hopes you'll get a solution that may help me.
If I do figure anything out i'll post back.
Click to expand...
Click to collapse
seems that this is a topic that has been posted on a bit over time with no real single culprit or fix. I'll post back if I figure anything out... I know in the Cyanogen thread, I saw info that stated that the MAC address of the phone was changing and I'm going to try and determine if that is happening to mine.

I have the same issue. Sometimes even when i pick up the phone, if i look fast enough i see that the Wi-Fi bars weren't even there! Thats only 1 out of 5 times though. The other time its usually just grey bars. Sometimes it actually will click back and they'll flash to blue and grey 2-3 times and then go solid blue. Then sometimes like you, they'll stay grey. I've tried everything too...reverting to stock, Different kernels, ROMs, routers, static IP, 2.4 or 5ghz, full auto mode. The only fix that makes it a little more reliable, is using Wi-Fi PM Fast. But even that, is not reliable. I'd say its about 50% reliable then, for a huge sacrfice in battery life. For me i've noticed this started to happen with 4.2. Before that i never had a problem. All other devices though no problem. My Nexus 7 is just fine. But the galaxy nexus, no matter what router or where i am, the Wi-Fi is totally unreliable. For me, it happens within 2 minutes that it will disconnect most times. Then 1 in 10 times it'll be fine for 10 hours.
In all honesty, i've given up. Just come to deal with it. Use mobile networks when i'm not needing to download. I can download files and stream music just fine too. If there is traffic going through, it never disconnects. But when its just sitting there without traffic, it disconnects, or, loses connection to google servers i should say.

well that's not good to hear...

I installed stock 4.0.4 a couple days ago and have not had my wifi go grey on me yet.
Sent from my Galaxy Nexus using Tapatalk 2

jrmacarthur said:
I installed stock 4.0.4 a couple days ago and have not had my wifi go grey on me yet.
Sent from my Galaxy Nexus using Tapatalk 2
Click to expand...
Click to collapse
yeah, I love Cyanogen so not willing to go back to stock... waiting for them to finish 10.1 and I guess I'll see how it behaves then.

Hi all,
Just to say that I have the same problem. I have been upgraded from ICS to 4.2 and nothing had happened but I had to downgrade to 4.1.1 (AOKP Build 4) due to other issues and after that I started notice the WiFi problem.
At first I thought it was when the screen went off, but I has happened with screen on too. I have to turn WiFi off and the back on to connect properly again, very annoying.
As I said I started noticing this after I downgraded, but then again, I had used AOKP 4.1.1 before without this issue. I think that it is time to change my phone :/

tgeery said:
so, I've read around here on the XDA forum about problems with wifi connectivity where we have full bars for wifi but they are gray and you are not getting out. many describe my situation but I've not seen any real solutions...
my problem is that I can connect to my wifi router without issue but then a random amount of time later, sometimes fairly quickly and sometimes it's hours later, I will pick up the phone and see full bars but they are gray and I'm not getting out. I can try opening a terminal window and pinging the gateway/dns servers and can't even reach the gateway.
things I have tried:
- turned off MAC filtering on the wifi AP
- switched from a 5 GHZ wifi on the AP to 2.4 GHZ net on the AP and vice versa
- manually set the phone wifi preference to one or the other (5 or 2.4)
- battery pull on the phone
- delete network settings for my AP and reconfigure
I have not yet tried a static IP config on the phone but I can easily try that... {edited to add} well, I tried static config and that didn't help at all...
one other tidbit of info, I have a work Blackberry with wifi and it never loses wifi connectivity so this is a problem unique to my Nexus.
I'm running Cyanogen 10.0.0-toro and no, I haven't tried a full wipe and reload yet.
thoughts or suggestions?
Click to expand...
Click to collapse
I'm on Muzzy 4.2.2 and I'm currently having the same problem. It's not a new problem since I remember having it months ago (disabled my phone's WiFi because I kept missing emails and other notifications - grew tired of dealing with it). I thought it was my router, so I swapped it with a newer one recently, but it carried forward (old router was TRENDnet Draft N and the new one is ASUS RT-N66U).
I would like to know how to properly troubleshoot this problem.

I'm glad I didnt have to create a thread for this. I have been facing this problem quite a lot. I can confirm that WiFi works absolutely fine until 4.1.2, whether it is stock or CM10 (I havent tried the other ROMs yet). I have faced this problem only from 4.2. It still exists on 4.2.2. Happens on all the ROMs I have tried till now including CM10.1 nightly as well as the stock factory image.
When the phone is sleeping, it seems to lose WiFi connectivity and when woken up, the WiFi bars is grey though it is full. If I am very lucky, it will turn blue automatically. Most of the times, I have to switch WiFi off and back on for it to connect properly.
Anyone knows the root cause for this? In case this has been discussed in any other thread?

subhramani said:
I'm glad I didnt have to create a thread for this. I have been facing this problem quite a lot. I can confirm that WiFi works absolutely fine until 4.1.2, whether it is stock or CM10 (I havent tried the other ROMs yet). I have faced this problem only from 4.2. It still exists on 4.2.2. Happens on all the ROMs I have tried till now including CM10.1 nightly as well as the stock factory image.
When the phone is sleeping, it seems to lose WiFi connectivity and when woken up, the WiFi bars is grey though it is full. If I am very lucky, it will turn blue automatically. Most of the times, I have to switch WiFi off and back on for it to connect properly.
Anyone knows the root cause for this? In case this has been discussed in any other thread?
Click to expand...
Click to collapse
have you posted this information over in any of the threads where the developers are working such as Cyanogen in an effort to bring this issue to the forefront for more visibility?

I have had those wifi problems with every android version and rom I had on my GNex as far as I can remember.
Sometimes it will be able to reconnect but sometimes I have to disable and re-enable wifi to get it back.
I too thought that it might have been my crappy router as I have had multiple problems with it over the years (some Linksys router).
This is really annoying because it won't receive any e-mails until I randomly decide to have a look at my phone. :/

Fabur87 said:
I have had those wifi problems with every android version and rom I had on my GNex as far as I can remember.
Sometimes it will be able to reconnect but sometimes I have to disable and re-enable wifi to get it back.
I too thought that it might have been my crappy router as I have had multiple problems with it over the years (some Linksys router).
This is really annoying because it won't receive any e-mails until I randomly decide to have a look at my phone. :/
Click to expand...
Click to collapse
trust me, I understand your frustration... some days, I can go almost all day without loosing wifi data throughput and other days it won't last 10 minutes without going to gray bars.
unfortunately, no one is sharing any fixes which tells me that no one has a good handle on the problem.

Same issue for me on stock Android 4.2.2. Leave WiFi on overnight and when I wake up its connected to WiFi but gray bars...
Sent from my Galaxy Nexus using xda premium

The update to 4.2.2 drivers have fixed all WiFi issues for me. For the first time since 4.1 I can now use WiFi optimization now. And WiFi is fully reliable.

tgeery said:
so, I've read around here on the XDA forum about problems with wifi connectivity where we have full bars for wifi but they are gray and you are not getting out. many describe my situation but I've not seen any real solutions...
my problem is that I can connect to my wifi router without issue but then a random amount of time later, sometimes fairly quickly and sometimes it's hours later, I will pick up the phone and see full bars but they are gray and I'm not getting out. I can try opening a terminal window and pinging the gateway/dns servers and can't even reach the gateway.
things I have tried:
- turned off MAC filtering on the wifi AP
- switched from a 5 GHZ wifi on the AP to 2.4 GHZ net on the AP and vice versa
- manually set the phone wifi preference to one or the other (5 or 2.4)
- battery pull on the phone
- delete network settings for my AP and reconfigure
I have not yet tried a static IP config on the phone but I can easily try that... {edited to add} well, I tried static config and that didn't help at all...
one other tidbit of info, I have a work Blackberry with wifi and it never loses wifi connectivity so this is a problem unique to my Nexus.
I'm running Cyanogen 10.0.0-toro and no, I haven't tried a full wipe and reload yet.
thoughts or suggestions?
Click to expand...
Click to collapse
same thing happened to me on toroplus sourcery 5.1, after trying everything i could think of and talking to one of the devs, i finally did a fresh download of rom and gapps. wiped cache,wiped dalvik, factory reset, wipe system, deleted android folder off of storage then installed the fresh download of rom and gapps and its been working great for me since. hope this helps.

M3drvr said:
The update to 4.2.2 drivers have fixed all WiFi issues for me. For the first time since 4.1 I can now use WiFi optimization now. And WiFi is fully reliable.
Click to expand...
Click to collapse
Can you elaborate on this? I've flashed 5 different modems and still get this problem... it happens to my cell service bars, as well. Would love to know what the cause is.

aqcon said:
Can you elaborate on this? I've flashed 5 different modems and still get this problem... it happens to my cell service bars, as well. Would love to know what the cause is.
Click to expand...
Click to collapse
i just know ever since moving to a 4.2.2 kernel that has the 4.2.2 drivers my wifi has been stable. I know there was a post in the anarkia thread with the ak kernel that had the drivers. but i believe most any 4.2.2 kernel would have them implemented. i do have the newest bootloader and radio too. but i know as soon add i got the 4.2.2 drivers all issues were resolved wifi wise. of course i think if you have a 4.2.2 kennel you'll have them.

M3drvr said:
The update to 4.2.2 drivers have fixed all WiFi issues for me. For the first time since 4.1 I can now use WiFi optimization now. And WiFi is fully reliable.
Click to expand...
Click to collapse
I'm looking forward to that update - I've been watching the Cyanogen threads for when I think the 10.1 has matured enough to become my daily driver... good to know you've had positive results!

Temporary solution
me facing same issues , Solution would be to use an app called wifi fixer by zanish-g1 from the play store ...
it worked for me !! :good:

[Q] Another wifi bug thread, I've tried everything possible.

Hi!
I know there are plenty of threads about the wifi on this phone, I've read every one of them, posted in many places and have had no good outcome.
Here is my (lengthy) story.
Had annoying wifi bugs on stock 4.1.2, seemingly general lack of interest from the phone in connecting to wifi, but would generally connect after a reboot of both modem+phone+ disabling PSM (even then, not always )
6 months on stock go by, thought flashing a custom rom would fix everything and all would be well again, so I flashed PA.
An even more annoying bug showed up,
Turn wifi on > doesn't automatically connect, so I manually go to the wifi settings page and try connecting.
Before trying to connect - Full signal.
While trying to connect - Goes down to one bar while connecting > fails > then goes back to full signal.
Does occasionally connect, but it's rare. Rebooting both phone and the modem does nothing at all, seems to have a mood of it's own.
It's not just my wifi, but wifi at college too, other devices connect to the same access point just fine.
What would fix this? Will pretty much try most things now,I tried flashing NEAK too.
I don't have a data plan either, so my phone is basically useless without wifi, I've resigned to using my laptop all the time.
Thank you for reading this so far, I'd be thankful for ANY advice.
TL;DR :- Annoying wfi bug, tried every 'solution' I've heard of, nothing worked, never buying a Samsung again :crying:
(Attached images of the phenomenon)
UPDATE:- Just like stock, it will only connect if I am a foot away from the router, irrespective of how much signal I have. Even if I have a full signal elsewhere, it won't connect

dude u r running AOSP :silly::silly:
try TW Rom and see if the problem exists

yahyoh said:
dude u r running AOSP :silly::silly: try TW Rom and see if the problem exists
Click to expand...
Click to collapse
We meet again!
Like mentioned in the post, the only reason I flashed an aosp based ROM was in the desperate hope it'd rid the phone of its WiFi problem.
Thought a custom ROM would do what Samsung refuses to do.
Hope someone has a valid solution for this.
Sent from my Galaxy Note II using Tapatalk 2

Anyone?
I forgot I already had the range issue for quite a while, even on stock.
I had tried everything, including static IP, wps, and whatever else was stated to work.
Does anyone know of a working solution to this? Is this a hardware/software issue?
Sent from my Galaxy Note II using Tapatalk 2

WiFi not working properly v20b

I have installed v20b, everything works fine except WiFi: after sometime the connection just doesnt work and i have to turn off and on again the WiFi. This just happened to me at least 10 times

ImSpiderman said:
I have installed v20b, everything works fine except WiFi: after sometime the connection just doesnt work and i have to turn off and on again the WiFi. This just happened to me at least 10 times
Click to expand...
Click to collapse
try to reset your phone it should help and backup before i am also on v20b and no problems with wifi on my phone till now (upgraded and factory reseted)

I did it before flashing the rom because i was on cm13, dont think that another reset can help :/

ImSpiderman said:
I have installed v20b, everything works fine except WiFi: after sometime the connection just doesnt work and i have to turn off and on again the WiFi. This just happened to me at least 10 times
Click to expand...
Click to collapse
I do have this on IEEE 802.1X networks only. Also on Android 5.1. This seems to be regardless of root/no root.

Jens1969 said:
I do have this on IEEE 802.1X networks only. Also on Android 5.1. This seems to be regardless of root/no root.
Click to expand...
Click to collapse
Had WiFi dropouts on every LG ROM on this device.
It would drop on any WiFi network I tried. My old phone and all other devices have no issues at all.
Bit the bullet and unlocked bootloader and went to CM13, rock solid WiFi now. IMO LG's software is borked.

Adam86 said:
Had WiFi dropouts on every LG ROM on this device.
It would drop on any WiFi network I tried. My old phone and all other devices have no issues at all.
Bit the bullet and unlocked bootloader and went to CM13, rock solid WiFi now. IMO LG's software is borked.
Click to expand...
Click to collapse
Whats the easiest way to unlock BL? do you have to download the file from android thats 1 plus gig big and do it thru that ?

awes0me1 said:
Whats the easiest way to unlock BL? do you have to download the file from android thats 1 plus gig big and do it thru that ?
Click to expand...
Click to collapse
Right now there is only one way: LG Developer program.

I think that is problem with 6.0
My network is ipv4 and i think phone force ipv6. In developer options have option to use lollipop settings but i think that is not doing any better

There was an issue with Verizon 12B that was recalled with similar issues.
Never had Wi-Fi issues otherwise. It was patched in 13B

ImSpiderman said:
I have installed v20b, everything works fine except WiFi: after sometime the connection just doesnt work and i have to turn off and on again the WiFi. This just happened to me at least 10 times
Click to expand...
Click to collapse
Same with me on 20a... wifi connects but there's no internet connectivity. Then it comes good for a while but eventually drops the wifi connection completely. Sometimes it forgets the wifi password and I have to re-enter it. Makes the phone essentially useless on wifi. A factory reset seems to be the next step unless anyone has any other suggestions?

Same problem on 20b

The WiFi problem seems to have settled down for me now. I went on a binge of uninstalling and reinstalling apps, cleared all app caches, rebooted several times, and recited some incantations (mostly beginning with f). I haven't spent a lot of time using it on WiFi but it seems a lot more stable. Will keep an eye on it and see how it goes.

I came back to a stock based ROM from CM13 because the lack of camera functionality and all my WiFi dropouts are back again. This is really disappointing with this phone as it is completely random and none of my other phones/devices have ever had problems like this. End of my tether with it to be honest, this phone will be going on eBay at this rate.

Well I've been running catlog tonight and it didn't take long for the WiFi to blip.
If there are any catlog experts out there I would really appreciate it if anyone could have a look to see if there is any indication of what is causing this random disconnection and then reconnect shortly afterwards
Many thanks in advance.

Sorry, can't help with the catlog. But having same problems.
I did 3 hard-resets with always the same result: wifi works fine for 1-2 days, than breaks.
The connection is strong an seems stable but data-throughput and ping times are ugly (0,4 Mb down, ping around 2-3 seconds).
Here's a screenshot that perfectly shows the impact: same phone, same setup, same wifi. just 1 day between the tests.
i.imgur[dot]com/JYI7b9I.jpg (sorry, can not upload pics)
Any ideas how to fix this? a DNS problem?
btw: IPv6 is disabled on the router.

I have the same problem and i found a solution for me. I'm using pebble smartwatch with G4 and i noticed that when i disconnect my watch or turn off bluetooth, wifi stays stable. If you have a bluetooth device like me you can try this method.

PixPi said:
I have the same problem and i found a solution for me. I'm using pebble smartwatch with G4 and i noticed that when i disconnect my watch or turn off bluetooth, wifi stays stable. If you have a bluetooth device like me you can try this method.
Click to expand...
Click to collapse
I've also had my G4 get into a state where Bluetooth is stopping WiFi from working. I posted a thread about this here. To summarise, I've twice gotten into the state where my WiFi disconnects whenever I put the phone to sleep. When it wakes up, it takes ages to reconnect. Sometimes it fails to authenticate and forgets the password for the WiFi network. Even when it is connected, the connection is very flaky. This only happens when I'm on a 2.4Ghz network and Bluetooth is enabled - if I disable Bluetooth or switch to my 5Ghz network then WiFi is ok.
I've had this happen to me twice now... the first time was straight after the update to MM. I fixed it by uninstalling and reinstalling apps, and eventually it came good. After a few weeks the phone got into that state again. I tried clearing cache, factory reset, and reinstalling MM using the LG Bridge "Update error recovery" option and nothing helped. Once again I went through my apps one by one and uninstalled and reinstalled them and once again the phone came good.
This is a huge pain in the butt... not sure how long the phone will hold out before it gets into this state again. I really hope there's a MM update that addresses this soon.

sladflob said:
I've also had my G4 get into a state where Bluetooth is stopping WiFi from working. I posted a thread about this here. To summarise, I've twice gotten into the state where my WiFi disconnects whenever I put the phone to sleep. When it wakes up, it takes ages to reconnect. Sometimes it fails to authenticate and forgets the password for the WiFi network. Even when it is connected, the connection is very flaky. This only happens when I'm on a 2.4Ghz network and Bluetooth is enabled - if I disable Bluetooth or switch to my 5Ghz network then WiFi is ok.
I've had this happen to me twice now... the first time was straight after the update to MM. I fixed it by uninstalling and reinstalling apps, and eventually it came good. After a few weeks the phone got into that state again. I tried clearing cache, factory reset, and reinstalling MM using the LG Bridge "Update error recovery" option and nothing helped. Once again I went through my apps one by one and uninstalled and reinstalled them and once again the phone came good.
This is a huge pain in the butt... not sure how long the phone will hold out before it gets into this state again. I really hope there's a MM update that addresses this soon.
Click to expand...
Click to collapse
I've noticed my Bluetooth problem in two ways. One of them was connecting a Bluetooth speaker while the watch is connected. When i connected speaker too, wifi had no issues.
And the other situation that i made my wifi stable was going into safe mode. Even Bluetooth on i was able to connect and stay connected to wifi when i was in safe mode.
Which apps did you have to reinstall? Do you remember?
Sent from my LG-H815 using Tapatalk

ImSpiderman said:
I have installed v20b, everything works fine except WiFi: after sometime the connection just doesnt work and i have to turn off and on again the WiFi. This just happened to me at least 10 times
Click to expand...
Click to collapse
This not 6.0 issue This horror exist on 5.1. same...
I try som stuff but not working the issue still alive....

PixPi said:
And the other situation that i made my wifi stable was going into safe mode. Even Bluetooth on i was able to connect and stay connected to wifi when i was in safe mode.
Click to expand...
Click to collapse
Yes, I noticed this too... everything worked fine in safe mode.
Which apps did you have to reinstall? Do you remember?
Click to expand...
Click to collapse
I just started going down my app list and uninstalling apps which looked like they might have something to do with bluetooth, then putting the phone to sleep and waking it up to see if the problem was still there. I got a bit slack and maybe uninstalled two or three at a time before testing. I should have been more systematic about it but I wasn't really expecting it to work. I'm pretty sure the last one I uninstalled before things started working was TuneIn Radio so if you have that installed you might want to try uninstalling it. I've since reinstalled it and WiFi is still working.

wifi deep sleep issue (have to wake device to reconnect to wifi)

hey guys, I need some advice or assistance with a wifi issue on my D855 32GB, running Fullmics 6.1.
The issue is, every time my device goes into deep sleep, is inactive for a lengthy period, the wifi connection becomes dormant until i wake the device. Also, if i enter another area of saved wifi connection, I have to wake the device in order to get connected. For example; if I leave home wifi and enter work wifi I will not connect until i wake the device and vice versa (work wifi to home wifi no connection until device i awoken)
Please, can someone assist?
I did posted this before, got some answers saying it maybe marshmallow/doze related. If so, how do i make adjustments?
P.s. I tried several ROMs and same issue, however, when i first got my device, stock everything (Lollipop), the issue was non existent.
many thanks in advance fellow xda members.

grymmy said:
hey guys, I need some advice or assistance with a wifi issue on my D855 32GB, running Fullmics 6.1.
The issue is, every time my device goes into deep sleep, is inactive for a lengthy period, the wifi connection becomes dormant until i wake the device. Also, if i enter another area of saved wifi connection, I have to wake the device in order to get connected. For example; if I leave home wifi and enter work wifi I will not connect until i wake the device and vice versa (work wifi to home wifi no connection until device i awoken)
Please, can someone assist?
I did posted this before, got some answers saying it maybe marshmallow/doze related. If so, how do i make adjustments?
P.s. I tried several ROMs and same issue, however, when i first got my device, stock everything (Lollipop), the issue was non existent.
many thanks in advance fellow xda members.
Click to expand...
Click to collapse
I had/have same issue since first MM version of Fulmics, it was never fixed. You said you have it on other MM ROMs so I wont point fingers at Fulmics dev since not all users are experiencing it.
Things I tried to do to fix it:
NatusVincere said:
Yap, had the issue while I was on Fulmics.
Made my device useless since it repeated almost every time I turn off the screen so I had to drop this ROM and go to AOSP/CM based.
I tried changing modem to multiple versions, tried delaying doze, tried multiple kernels, tried same as you disabling app optimizations as well.
Click to expand...
Click to collapse
Only possible alternative solution instead of switching ROMs is to make device use internet connection full time, to make it never go to deep sleep.
Perfect app for that would be:
https://play.google.com/store/apps/details?id=com.nhiemhk.keepinglightconnection

Question ⚠️ Suddenly, The mobile data connection started to fail.

POCO F3
Suddenly, The mobile data connection started to fail.
It suddenly disconnects, and I have to turn airplane mode on and off to get it to connect again, but it doesn't take long, it varies, and the connection is lost again.
And when it's connected, it's very slow, but a lot, it went from a 15mbps connection (before the problem), to a .3mbps connection. I have installed several ROM'S, and nothing fixes it. Another thing I've noticed is that suddenly he also started using Roaming when he didn't have it before.

Update: Testing with another mobile, with the same SIMCARD, i can connect to my red 4G, but in this POCO F3, when i tried connect to 4g cant, I get a notification that the selected network cannot be connected, The only one that accepts me is the one with 4G R (I think it's roaming).

UPDATE: Also I think that is a problem of crash of the Band 28 LTE

My modem often crashes too, since I bought the phone last year. Standard ROM, no unlock/root, updates when FW goes out.
I mostly see modem crash when the phone switch from wifi to LTE to wifi to LTE etc when I go outside. At one point I notice I have no data connection, sometimes it displays the "no SIM card" icon, the modem program loops and crash and the phone becomes warm because of this and lose its battery real fast.
Only cure is to reboot the phone.

Hi, my phone just started having a very similar issue after working fine for almost two years. I am on T-mobile in US, where are you? Did you find out any more info on this?

stevencrayne2 said:
Hi, my phone just started having a very similar issue after working fine for almost two years. I am on T-mobile in US, where are you? Did you find out any more info on this?
Click to expand...
Click to collapse
The truth is that I never found out, what I did find out is that my IMEI of my cell phone had a report of theft (I bought it second-hand) and only 2 networks (from my country) grabbed me: "telcel and altán", of which altán only got roaming and only telcel got the original 4g, on the other hand "at&t and movistar", nothing, only the company detected me, but they didn't get a signal... No way, I gave up, I switched to the only one that if he caught me it was Telcel (even if he didn't want to).

stevencrayne2 said:
Hi, my phone just started having a very similar issue after working fine for almost two years. I am on T-mobile in US, where are you? Did you find out any more info on this?
Click to expand...
Click to collapse
A lot of people complain about modem crash since the beginning, Xiaomi never fixed it. It seems the problem is happening when switching cell towers/wifi. At one point you notice you have no data or the "no sim" icon, you have to reboot.

I was experiencing that a lot when I was on a MVNO for the major networks (Mint Mobile, Google Fi, etc.). Upon switching to AT&T Prepaid, I am experiencing far, far fewer disconnects. Some particular locations will give me the exclamation point, but by and large it's much better.

It seems everyone is torn in half, between this glitch being software related, or hardware related.
I have tried everything to blocking out certain bands with network guru, to taking my phone apart and looking for some kind of issue. Been through countless roms, and firmwares, and kernels. I've gotten a new Sim card too. Have tried Compressed air. with nothing seeming to solve this issue permidently.

Zinnz said:
It seems everyone is torn in half, between this glitch being software related, or hardware related.
I have tried everything to blocking out certain bands with network guru, to taking my phone apart and looking for some kind of issue. Been through countless roms, and firmwares, and kernels. I've gotten a new Sim card too. Have tried Compressed air. with nothing seeming to solve this issue permidently.
Click to expand...
Click to collapse
For what it's worth, I'm also using a custom ROM (Arrow OS 13). I recall a while back there being kernels people developed that attempted to address the phone restarting issue.

Veiranx said:
For what it's worth, I'm also using a custom ROM (Arrow OS 13). I recall a while back there being kernels people developed that attempted to address the phone restarting issue.
Click to expand...
Click to collapse
Phone does not restart. It's just that at one point, you notice your data are not working, you cannot enable them, nor make phone calls, you may have the "no sim" account, your phone may go warm because the modem is constantly restarting.
In the end, you have to reboot your phone and everything is normal again.
As it about always happens while outside, I cannot connect a usb cable to dump logcat or others.

Magister54 said:
Phone does not restart. It's just that at one point, you notice your data are not working, you cannot enable them, nor make phone calls, you may have the "no sim" account, your phone may go warm because the modem is constantly restarting.
In the end, you have to reboot your phone and everything is normal again.
As it about always happens while outside, I cannot connect a usb cable to dump logcat or others.
Click to expand...
Click to collapse
Try to put some pressure on the phone screen, not too much, push down slightly or press it together in your hands while holding volume up volume down and power button. Let me know if this helps

Zinnz said:
Try to put some pressure on the phone screen, not too much, push down slightly or press it together in your hands while holding volume up volume down and power button. Let me know if this helps
Click to expand...
Click to collapse
Were you listening to something on Bluetooth via mobile data?
were you driving?
What was the ambient temperature in the room or outside when this occured?
Just trying to narrow down hardware or software.
My poco f3 likes to reboot with the no Sim error, when I'm driving around on mobile data, listening to Spotify via Bluetooth.
I'm curious what circumstances other users have encountered this error in, or what they were doing at the time when it occurred

As it happens about only when I'm outside, I can be driving (phone connected in BT) or walking.
But my phone never reboots, never.