Develop Bugs

Gone are the days of sim swapping???

This is more of a general ATT thread, but it does relate to my note 4.....
I have a one plus one, and my note 4 and from day to day I want the flexibilty to swap phones as I see fit. It used to be move the sim, and you're good. Lately, I've see issues when I moved my sim from phone to phone.
The first was last week, I bought an alpha clone off of craigslist and voice would work, but data would not. I dropped it back into my one plus one, and same thing, no data. Went to an ATT store, and they did an IMEI swap on my account and all was well in the world. Years ago, the IMEI swap on the carrier system kinda just followed the phones and wasnt ever an 'official' thing...but now it seems it is. Any ideas on this, can I swap my IMEI online with ATT?
Obviously I did a search on it, and it takes me to the ATT website, but it looks more along the lines of swapping when you've made an official order, not just because you want to. Am I missing something?

Change the sim card. When I went from my g2 to a nexus 5 I swapped the sim when I got the nexus 5 in the mail and data wasn't working ect. I go down to the AT&T store and talk to the same girl who's actually on the ball there and we found out that if you have an ICIS sim card it won't work on phones they don't sell. Just get a generic lte sim and see if that fixes it. Good luck!

The Sims that are blue are lte Sims don't get the ones that are purple those are isis

Clienterror said:
Change the sim card. When I went from my g2 to a nexus 5 I swapped the sim when I got the nexus 5 in the mail and data wasn't working ect. I go down to the AT&T store and talk to the same girl who's actually on the ball there and we found out that if you have an ICIS sim card it won't work on phones they don't sell. Just get a generic lte sim and see if that fixes it. Good luck!
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Click to collapse
Is that what ATT is giving out by default now? I have a nano sim (that i got for that nexus clone) and it works fine in my OPO. If I put it in my note 4, I only get 4G, not LTE, which I thought was odd. I can do as suggested, just want to make sure I understand first...

All att Sims are lte capable but the purple ones are softcard (isis) compatible, meaning they have the correct security features for the use of isis enabled devices

thanitos said:
All att Sims are lte capable but the purple ones are softcard (isis) compatible, meaning they have the correct security features for the use of isis enabled devices
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ok, so he meant isis above.
I think this is just a standard att LTE card...its orange...and it DOES work in my OPO, so I think that theory is out.

Call customer care and give them the imei of a phone that supports lte and have them add that and just not change the sim

dboogie2288 said:
ok, so he meant isis above.
I think this is just a standard att LTE card...its orange...and it DOES work in my OPO, so I think that theory is out.
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The Isis/Softcard is a problem as described above, but there's also a "nextgenphone" feature that goes on your account with newer phones (along with your normal data feature) and newer phones are using that with a related APN so it could have something to do with that new feature. Haven't figured it out yet but I'm playing with the system & I'll post what I find. So far all my secure sims have changed phones fine. My Gear S gave me a couple problems but I'm not sure if they were related.

zoso28 said:
The Isis/Softcard is a problem as described above, but there's also a "nextgenphone" feature that goes on your account with newer phones (along with your normal data feature) and newer phones are using that with a related APN so it could have something to do with that new feature. Haven't figured it out yet but I'm playing with the system & I'll post what I find. So far all my secure sims have changed phones fine. My Gear S gave me a couple problems but I'm not sure if they were related.
Click to expand...
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Interesting. When I went to another ATT store a few weeks ago to change to a nano sim, the rep changed some codes on my plan. I got this in an email:
DELETED MOBILESHAREVSL64VT
ADDED MOBILESHAREVP20
Last night I went to a different ATT store than usual, and found out they were just a partner (though you could never tell it) and he said there were a few wonky codes on my plan, one of which mentioned something about APNs...so maybe youre on to something. He was under the impression it was grandfathered though, so it was old. He could, of course be wrong.
He also tried his SIM (oh and I have a non-secure sim) in my one plus one from his moto x 2014 and it worked just fine. LTE and everything. He put my sim into his X, and got 4G only, no LTE.
So he swapped me back into a non-secure micro sim, just to try things out again, and I left the store with my one plus one working. I came home, dropped it into my Note 4, and got 4G only, no LTE. When I put it back into my OPO, I got a text message saying I needed a new sim to work with my phones new feature. Weird.

The original feature is just normal mobile share data but I'll have to look up the second one I haven't seen that in the system. What i know is that once you put your sim in a newer phone (last few months) the system auto adds that nextgen feature & you end up either needing a secure sim or have to put the correct imei on the account

zoso28 said:
The original feature is just normal mobile share data but I'll have to look up the second one I haven't seen that in the system. What i know is that once you put your sim in a newer phone (last few months) the system auto adds that nextgen feature & you end up either needing a secure sim or have to put the correct imei on the account
Click to expand...
Click to collapse
So that sounds like its our culprit.
If i have a secure sim for my note 4....can I move that to my OPO? I've heard no, but I've also heard yes...

I have been swapping my Sim card that I got with my Note 4 with my Note 3 Nokia 1520 and my Gear S. I have had data act up but only with the Note 4. Everything else has worked fine. In the Note 4 what I have done is add the older apn and toggle to that apn. Let it pickup the 4G lte icon or whatever it is. Got to phone app settings advanced settings and make sure you don't get an error. Then switch back to the Nextgen apn.
Worked for me.
Sent from my SAMSUNG-SM-N910A using XDA Premium HD app

For Christmas I got an iPhone 5s for my daughter,to replace her iPhone 4s.Its been so long since I've used an iphone. Christmas morning she opened it.I told her just swap your Sim card,she came back down kinda upset and said it didnt fit.Now I felt bad,ATT isn't open nothing I could do.I remembered once I took a Sim that was too small and crazy glued it to a iPhone 3g Sim tray and it worked.So I googled cutting an iPhone 5s Sim card,and there's actually a template you can DL and trace where to cut.For some reason my printer didn't want to work so used a ruler and the dimensions that were on the site,it was micro Sim to nano sim. I got really sharp heavy duty scissors and cut it,sanded the sides and corner,even the non contact side because the nano is like a hair thinner,fit right in sim tray and worked perfect.I've offered to give her my S5,nope lol these kids and there Iphones.And that phones IMEI was on my plan that day,it was an ATT phone from someone who recently got a 6plus that I got it from.

International Unlocked Note 7 with AT&T

First and foremost, I'm a noob.
Anyways, I'm giving this whole Android thing a go for the third time. I had an S7 and an S7 Edge, both were great phones but they were also carrier versions. I've owned pretty much everything Apple and coming to the realization that Apple is dropping the ball. It's time to switch it up.
I ordered an International Unlocked 930F Note 7 and I'm currently with AT&T. After researching, I'm aware that I'll be losing a few things like Samsung Pay and VoLTE. Few questions I have: When the Note comes in the mail, shall I remove the SIM out of my iPhone SE and insert it into the new phone? Or go to an AT&T store and ask for another SIM?
Your feedback/suggestions are greatly appreciated!

Someone will correct me if I am wrong but I don't believe you will lose Samsung Pay. It should work. And yes, just plug your SIM (if its a nano) and go. I plan on getting the same phone and I had the S7 Edge international version and it worked fine on AT&T. I never tried Samsung pay though.

Thanks for the quick reply.
Not too worried about Samsung Pay, as I don't even use Apple Pay. But the VoLTE is what I'm mainly concerned about.
Also what about visual voicemail? I understand it can be downloaded from Google Play, but will it still work and keep my same greeting, etc..?
Brings me to next question: Samsungs website offers the micro SD card as a free gift when purchasing the phone, do you know if they honor purchases from eBay and/or international devices?

Yeah I don't use Samsung pay either. Not sure about VoLTE.
Visual voice mail works fine. Just download the app from the Play Store like you said but not sure about the greeting. Don't know if that stored in the app or on AT&T's server.
From what I've been reading, when you register your phone, regardless of where you got it, you will be able to take advantage of the current promotion. LETS HOPE!

Samsung pay should still work, and so will the VVM app from the play store.
Eventually if a root/flashing method should come out for the international model which could let you flash over AT&T stuff such as HD voice. Not 100% sure on that but maybe someone else can verify that.
When you get the phone, go to the store and ask for a sim.
As for the free gift, it only applies if you buy it from a carrier store, or certain stores. I'm assuming the guy you bought it from already got the promo gift from Samsung. If you really want it maybe cancel the eBay order and get it from Samsung.

As far as I know you can't buy the international version straight from Samsung. If that would have been an option, I'd been all over that.
Would the SIM in my iPhone not work?

Seems you may be right, the only options I see on their site are carrier models. If you go to the promotion site though, they have an option for "other" retailers so you can try with your eBay invoice as proof of purchase.

I like where your heads at.
I suppose what I can do with the SIM is try swapping it into the Note and if it doesn't work, go to the store.

mattjewell said:
I like where your heads at.
I suppose what I can do with the SIM is try swapping it into the Note and if it doesn't work, go to the store.
Click to expand...
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I'll pop in with a lil info for you. I use a international Note 4 on AT&T now with zero issues. A few reasons why I went with this version instead of a carrier branded phone. First one was the unlocked bootloader, since the AT&T version was locked up and still locked to this day. My 4 still works perfectly fine with a custom S7/Note 7 Rom on it. So you decide if you want it..
Now in regards to the crapple sim going into the N7, if I'm not mistaken you're going to have to get that changed from the crapple set-up. Think they need to put it back to regular data or whatever all the other phones use. You know it's always something special with crapple! I would say try the sim if no data you'll know why.
Good luck
Bajan

mattjewell said:
I like where your heads at.
I suppose what I can do with the SIM is try swapping it into the Note and if it doesn't work, go to the store.
Click to expand...
Click to collapse
As mentioned above, I believe Apple uses different settings for data with their sim cards. When my brother switched from a 4S to Android he had to get a new card. I also just got his LTE working for him by contacting support and registering his Sim card with the one I from a store display phone. I just took a picture of the IMEI of an S7 in store and used the "ATT Phone" APN settings. The NXTGENPHONE APN will not work for some reason when I tried it.

cadcamaro said:
As mentioned above, I believe Apple uses different settings for data with their sim cards. When my brother switched from a 4S to Android he had to get a new card. I also just got his LTE working for him by contacting support and registering his Sim card with the one I from a store display phone. I just took a picture of the IMEI of an S7 in store and used the "ATT Phone" APN settings. The NXTGENPHONE APN will not work for some reason when I tried it.
Click to expand...
Click to collapse
While I'm at the store, I'll snap a pic of the back of an S7 as well just to be safe. Can you clarify "ATT Phone" in the APN settings? Where is this located?

Go into the phone settings and get the IMEI and IMEISV
I needed both when talking to tech support.
As for the APN I used the same ones as the OP from this thread.
http://forum.xda-developers.com/verizon-s7-edge/how-to/verizon-s7-edge-sm-g935v-att-lte-tip-t3429897

Anyone using this on Verizon yet?

Just want to verify this phone works appropriately with Verizon. I see nothing on this from Verizon's website and nothing more than a few mentions in press releases. Does the lte-a work correctly? Can we access Verizon features like video calling? Does Verizon staff give you problems trying to register the phone?
Can't wait to hear some first hand experience.

wondering the same thing actually

https://opendevelopment.verizonwireless.com/device-showcase/device/7466
Looks good enough for me. I'm about to order one from clove, will update when it gets here if this thread still needs some answers. I hope volte works. Wifi calling would be a cherry on top.

Yup! Having it working on my XZ2 Compact. Didn't originally want to connect, so I flashed the OEM+OEM_Other.sin files from the US version and now I have Verizon working without a hitch. VoLTE is enabled for Verizon by default since it can only connect over LTE to begin with, but no WiFi calling. That being said and it being a dual SIM device, my secondary T-Mobile SIM has access to neither VoLTE or WiFi Calling. So I have calling set up for Verizon and Data over T-Mobile. You're able to do dual LTE standby on this device.

So now that this works with Verizon I should be able to buy the duel sim version and run both my personal At&t sim and my Verizon work sim card in this phone with duel standby? No flashing any software?

themoveforward said:
[...] ... I flashed the OEM+OEM_Extra.sin files from the US version and now I have Verizon working without a hitch. [...]
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Does flashing these have any affect on DRM keys and such? I'm going to be getting a H813, but with UK software from clove so I'll need to do the same thing I'm guessing.

Ziltoid_ said:
Does flashing these have any affect on DRM keys and such? I'm going to be getting a H813, but with UK software from clove so I'll need to do the same thing I'm guessing.
Click to expand...
Click to collapse
Are the frequency's for both of these phones the same? Only difference would be that one is duel sim and the other isnt correct?

mattnathaniel12 said:
Are the frequency's for both of these phones the same? Only difference would be that one is duel sim and the other isnt correct?
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I believe so. H8324 is the Asian dual SIM and H8314 is the Western single sim. I wasn't checking all the bands but both phones have all three of Verizon's LTE bands supported

Ziltoid_ said:
I believe so. H8324 is the Asian dual SIM and H8314 is the Western single sim. I wasn't checking all the bands but both phones have all three of Verizon's LTE bands supported
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Click to collapse
Just ordered the duel sim version and should have it by Wednesday. I currently have both an At&t personal phone and a Verizon work phone. Plan is to combine them both in this duel sim phone and only have to carry one haha. If it doesnt work out for whatever reason il just try google voice for my work number i suppose.

themoveforward said:
Yup! Having it working on my XZ2 Compact. Didn't originally want to connect, so I flashed the OEM+OEM_Extra.sin files from the US version and now I have Verizon working without a hitch. VoLTE is enabled for Verizon by default since it can only connect over LTE to begin with, but no WiFi calling. That being said and it being a dual SIM device, my secondary T-Mobile SIM has access to neither VoLTE or WiFi Calling. So I have calling set up for Verizon and Data over T-Mobile. You're able to do dual LTE standby on this device.
Click to expand...
Click to collapse
Having some issues with my XZ2 Compact Duel sim. With At&t I am only getting H and H+ connection and Verizon I cant seem to get anything to work. What APN did you pick for your Verizon sim, i have choices of CBS, FOTA, IMS and Internet.

So I have some more information that may help someone or may not. After talking with Verizon in depth about my issue with connecting to their service they have determined that the XZ2 Compact will not work on their service. Even with it being labeled as an Certified Open Market device on their own site and even being listed as Verizon Compatible on Bestbuys site and many others. They said noone there has any knowledge of the device coming to Verizon at all and were confused about it being posted on all the sites as being Certified. So i suppose it just wont be compatible lol. I guess im porting my 2nd # over to at&t and just not dealing with it because im sure as heck not going through the hassle of sending this phone and the chargers and cases back lol. If anyone has any success on getting this connected with Verizon please post, but im not hopeful lol.

mattnathaniel12 said:
So I have some more information that may help someone or may not. After talking with Verizon in depth about my issue with connecting to their service they have determined that the XZ2 Compact will not work on their service. Even with it being labeled as an Certified Open Market device on their own site and even being listed as Verizon Compatible on Bestbuys site and many others. They said noone there has any knowledge of the device coming to Verizon at all and were confused about it being posted on all the sites as being Certified. So i suppose it just wont be compatible lol. I guess im porting my 2nd # over to at&t and just not dealing with it because im sure as heck not going through the hassle of sending this phone and the chargers and cases back lol. If anyone has any success on getting this connected with Verizon please post, but im not hopeful lol.
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I love Verizon but I was actually thinking of going to AT&T myself tired of Verizon having such a limited phone selection. However there is a post in this thread by the name of themoveforward or something who claims he got this working on verizon you may want to try his methods before making the switch

R_Fated_Circle said:
I love Verizon but I was actually thinking of going to AT&T myself tired of Verizon having such a limited phone selection. However there is a post in this thread by the name of themoveforward or something who claims he got this working on verizon you may want to try his methods before making the switch
Click to expand...
Click to collapse
I tried sending him a message but haven't heard back. I'm assuming perhaps he was mistaken about what phone this post was referring to.

I believe carol_vzw is a Verizon employee who maintains this list: https://community.verizonwireless.com/docs/DOC-2843
The H8314 is listed on here as officially supported, but H8324(dual SIM) is not. You could try messaging her on there to see if they can add the H8324, or find out why it's not compatible.
Edit: looks like you've already seen this based on the comments

Ziltoid_ said:
I believe carol_vzw is a Verizon employee who maintains this list: https://community.verizonwireless.com/docs/DOC-2843
The H8314 is listed on here as officially supported, but H8324(dual SIM) is not. You could try messaging her on there to see if they can add the H8324, or find out why it's not compatible.
Edit: looks like you've already seen this based on the comments
Click to expand...
Click to collapse
Yea the crazy thing is while talking to Verizon support yesterday i referenced that post and also Bestbuy having it labeled as for Verizon as well as the phone being posted on their Showcase directly on the Verizon site lol. The support guy kept putting me on hold and said he was taking the info as I was giving it to him to another support team directly and that they were all baffled at this information as none of them had any knowledge of this phone let alone it supposedly being compatible with Verizon at all. After about an hour into the call a woman picked up the phone and directed me to attempt to put my new sim card (when i swapped to this phone i had a micro-sim from my old phone not a nano-sim which this phone needs) directly into someone elses phone that has Verizon and attempt to activate the sim card on their phone, then attempt to reinsert it back into my phone to see if the network picked up. I will be attempting this in about an hour when I see a friend who has Verizon. I will update on whether this works or not.

mattnathaniel12 said:
Yea the crazy thing is while talking to Verizon support yesterday i referenced that post and also Bestbuy having it labeled as for Verizon as well as the phone being posted on their Showcase directly on the Verizon site lol. The support guy kept putting me on hold and said he was taking the info as I was giving it to him to another support team directly and that they were all baffled at this information as none of them had any knowledge of this phone let alone it supposedly being compatible with Verizon at all. After about an hour into the call a woman picked up the phone and directed me to attempt to put my new sim card (when i swapped to this phone i had a micro-sim from my old phone not a nano-sim which this phone needs) directly into someone elses phone that has Verizon and attempt to activate the sim card on their phone, then attempt to reinsert it back into my phone to see if the network picked up. I will be attempting this in about an hour when I see a friend who has Verizon. I will update on whether this works or not.
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Click to collapse
If its any hope, I had a similar situation when I was trying to activate my Nexus 5x on Verizon. The people in the store didn't know that it existed and had no instructions on what to do. Also my first nano SIM phone, and they couldn't get it to activate. That's when I learned to never go to their stores for technical help. But it was worth it that time because they let me keep the sim card and later I was able to get someone on their tech support number who was able to activate it remotely. It could just be that the phone is new and information hasn't gotten around internally. Verizon seems pretty bad about that.
My xz2c single sim package got lost on Wednesday by DHL ? but I'm going to be dealing with this soon

Well no luck trying to activate the Sim with another Verizon phone. It seems that the phone just isn't in the Verizon system yet.

I have a UK single sim that I'm having no service with Verizon. Not sure if it's due to the phone being from the UK or something else with Verizon maybe. Trying to flash the US firmware but having problems with Newflasher.
If I have any luck I'll post back here.

Just posting for others who may be curious; I was able to get the phone working on Verizon today. Using the sim from an already activated pixel 2 initially worked for data and calling, and sending text messages, but I could not receive text messages. I grabbed an updated sim (says 4G LTE on it) and activated it on the pixel 2, then moved it to the xz2c and currently have everything working. It's only been a few hours so we'll see if it stays like this or if it goes the way of the htc U11 and has problems every couple of weeks. I'm using the verizon approved H8314 single sim model, not the dual sim model.

Interesting, thanks for the update! I'm using an activated sim from my Pixel 2 as well. It says 4G LTE on the sim too and my model xz2 compact is the same H8314. So maybe it is the UK firmware in my case, I'm going to keep trying to figure out my drivers issue this weekend to flash US firmware and see if that helps.

Question Using an eSim without a physical Sim on AT&T

Hi, I'm trying to use an eSim only (without inserting a physical sim) on my pixel 6 pro on AT&T, however I cannot get it to work. When I say not get it to work, I mean with eSim only there is no cell signal and no data signal. Physical sim works fine on both signal and cellular service. If there's another Us AT&T pixel 6 pro user who's using only the eSIM for service please respond and let me know whether or not eSim only works for you. Thanks.

Not an AT&T user here, am using a European carrier, just from anecdotal perspective: I also use eSim only and never had an issue on my P6 Pro. So it appears to be something carrier related.
I remember that I had to activate my eSim, maybe you also have to do this? Did you try out the eSim/your contract before using this phone?

Morgrain said:
Not an AT&T user here, am using a European carrier, just from anecdotal perspective: I also use eSim only and never had an issue on my P6 Pro. So it appears to be something carrier related.
I remember that I had to activate my eSim, maybe you also have to do this? Did you try out the eSim/your contract before using this phone?
Click to expand...
Click to collapse
Yes, I tried 3 times with the help of AT&T and we couldn't get it to work. I'm going to return the device for a new replacement to see if that fixes this issue. Thanks for replying.

d.cortez said:
Yes, I tried 3 times with the help of AT&T and we couldn't get it to work. I'm going to return the device for a new replacement to see if that fixes this issue. Thanks for replying.
Click to expand...
Click to collapse
Before going through the hassle of returning the device for a potential fault - do you have a family member or friend, whose simcard/esim you could try out? That way you can find out if your phone truly has a defect or if its your contract/the specific esim. Of course you can always let them replace your device, but that will take a couple days, maybe there are faster ways to narrow the problem down.

Morgrain said:
Before going through the hassle of returning the device for a potential fault - do you have a family member or friend, whose simcard/esim you could try out? That way you can find out if your phone truly has a defect or if its your contract/the specific esim. Of course you can always let them replace your device, but that will take a couple days, maybe there are faster ways to narrow the problem down.
Click to expand...
Click to collapse
i tried again today at another AT&T corp store and walked out of the store with it working as expected (wait till the end). the person helping did additional research on my issue and discovered the P6P shipped to me "was not activated" with the inserted physical sim (which i removed when i received the device). apparently, AT&T will park (or associate) a new device with a specific number when shipping to you vs. walking in to buy a device on an existing line. nonetheless, i'm going to return the phone because the data connection isn't working consistently; data is on and then after i go to website, data turns off. i'm probably going to send it back to AT&T next week.

Finally got the phone working, but will get an unlocked version later; this one is still going back to ATT.

I'm using an ESIM on AT&t and even originally got the phone My plan was to have a physical TracFone SIM card and my AT&t esim which is exactly what I had on my Pixel 5 and it worked great. Both SIM cards work great... when the other ones not active or inserted. It is impossible to use with both SIM cards like I did on my Pixel 5. Constant signal loss and the majority of the time. No signal at all. But as soon as I deactivate or remove a SIM card it starts working perfect.

I had a problem with provisioning eSim on my TMobile, well technically its sprint still, says tmobile esim but I am on sprint billing. Anyways, you need to maybe try to do it on another WiFi access point or something. I had issues with mine activating over Viasat2 satellite internet. I live in that area, its either LTE or satellite for internet. Had to tether to my work verizon phone to activate it on sprint/tmobile lol. If the connectivity to the esim server is not great, you'll split hairs until it is.

spawn985 said:
I'm using an ESIM on AT&t and even originally got the phone My plan was to have a physical TracFone SIM card and my AT&t esim which is exactly what I had on my Pixel 5 and it worked great. Both SIM cards work great... when the other ones not active or inserted. It is impossible to use with both SIM cards like I did on my Pixel 5. Constant signal loss and the majority of the time. No signal at all. But as soon as I deactivate or remove a SIM card it starts working perfect.
Click to expand...
Click to collapse
Exactly the same issue/behavior I had with my AT&T P6P on the AT&T network so I returned mine today. I'm contemplating a Fi version to see if it works for my use case.

Note 10+ 5G Unlocked N976U stopped macking/receiving calls ATT

Hi guys,
My Samsung Note 10+ stopped making receiving calls about two weeks ago.
I have no option for VoLTE if that was the case; I updated my firmware to the last available (Android 12). I called customer service, and they did their "magic" with my IMEI and ID e t. c. I also went to their office, and they said they couldn't help me, but they have customers with the same issues with non-att phones.
Any solutions?
Thank you!

It's whitelisted.
*#*#4636#*#*, device info, enable VoLTE provisioned.

blackhawk said:
It's whitelisted.
*#*#4636#*#*, device info, enable VoLTE provisioned.
Click to expand...
Click to collapse
Thank you for your reply.
VoLTE provisioned is inactive.
Please, see the screenshot attached.
How can I activate it?

Not sure, but that's the problem.
Did you get a new sim card for it?

I got it a year and half ago. I will replace it today just in case.

Konfl1kt said:
I got it a year and half ago. I will replace it today just in case.
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The sim card needs to be configured for 4 VoLTE.
My N10+ was already running it, nothing happened after the switch.

Just got a new Sim. Nothing changed.
Still can't make and revcieve calls.

Konfl1kt said:
Just got a new Sim. Nothing changed.
Still can't make and revcieve calls.
Click to expand...
Click to collapse
Was this originally an ATT phone?

No, originally Samsung US version, unlocked.

I have a N975U1 and a new N975U. These are both 4G only variants, no 5G*.
The N976U however is whitelisted by AT&T and should work.
I haven't fully configured the unlocked variant so after reading this thread I was wondering what it do. It hasn't been booted since the switch.
Slammed it the sim card and booted; it's working the same as it's sister.
Try clearing the system cache.
Network reset.
Reset on AT&T's side.
*5G Versions: SM-N976F (Global); SM-N976U (USA); SM-N976N (South Korea)

Thank you. My version is the US version. All those things are done. I think I will change the carrier. ATT is just doing nothing.

Konfl1kt said:
Thank you. My version is the US version. All those things are done. I think I will change the carrier. ATT is just doing nothing.
Click to expand...
Click to collapse
Something is misconfigured.
It may be the new sim card or ithe sim card may be damaged; install a new one yourself and handle it like a stick of ram, it's ESD sensitive.
Talk to Advance tech support at AT&T, get someone that knows what they're doing... may take a few tries.
Also clear the data in the sim toolkit app in addition to what I already suggested.
Try a hard reboot as well.
Access point names settings should be this:

blackhawk said:
Something is misconfigured.
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I can't add NXTGENPHONE or ENHANCEDPHONE. It disappears right after saving.
There are many people with the same issue on the ATT forum. Many of them spent days talking to the support team; I tried it four times already and went to their office twice. Nothing helps, unfortunately.

Konfl1kt said:
I can't add NXTGENPHONE or ENHANCEDPHONE. It disappears right after saving.
There are many people with the same issue on the ATT forum. Many of them spent days talking to the support team; I tried it four times already and went to their office twice. Nothing helps, unfortunately.
Click to expand...
Click to collapse
I think the problem is the sim card.
On my unlocked new N10+ variant all I did to set it up was slam in the sim card from my other AT&T N10+. I didn't touch any settings on it.
How to set up Access Point Name (APN) on Samsung Mobile? | Samsung SG
FAQ for Samsung Mobile. Find more about 'How to set up Access Point Name (APN) on Samsung Mobile Device?' with Samsung Support
www.samsung.com

blackhawk said:
I think the problem is the sim card.
Click to expand...
Click to collapse
Yesterday, I got a new one—the same story with two sim cards.

Konfl1kt said:
Yesterday, I got a new one—the same story with two sim cards.
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Click to collapse
Check the card and make sure it's seated properly...

blackhawk said:
Check the card and make sure it's seated properly...
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Click to collapse
I did. The first card I tried to clean with alcohol as well. It stopped working overnight. The new one I tried to reinstall twice.

Konfl1kt said:
I did. The first card I tried to clean with alcohol as well. It stopped working overnight. The new one I tried to reinstall twice.
Click to expand...
Click to collapse
Maybe the phone side contacts.
I will remind you again the these circuits are suspectable to ESD damage. May fail instantly or days, weeks, even years latter.

Konfl1kt said:
I did. The first card I tried to clean with alcohol as well. It stopped working overnight. The new one I tried to reinstall twice.
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Click to collapse
After reading all of this, the only thing I have seen in regards to ATT not making calls is with WIFI calling if it does not have the carrier bloat.
You may have fun trying to find the user data file for ATT to flash for N976U.
If you could, load the carrier bloat U package and see if it resolves the issue.
The only other thing I have seen is when ATT deems a phone incompatible, they just suspend the SIM card and make it inactive. If the phone is whitelisted it shouldn't do this.
The best thing would be to go with someone like T-Mobile who won't mess with your SIM etc.

yygemmi770 said:
You may have fun trying to find the user data file for ATT to flash for N976U.
Click to expand...
Click to collapse
I did. I found it here. I tried different firmware. Nothing helps. I already ordered 22 Ultra. I didn't want to upgrade now, but I can trade in my old galaxy. In this case, it's acceptable for me.