OnePlus 7TPro service issues

Must mean that 3g shutdown has completed in your area as of yesterday.

Unfortunately, the OnePlus 7T Pro [McLaren] is not on the whitelist of acceptable phones and it will not do LTE/VoLTE calls.

https://www.att.com/idpassets/images/support/pdf/Devices-Working-on-ATT-Network.pdf

@Holvy - Hey man, so ATT and all the "official" people here will tell you that your phone is no longer compatible with the network, but don't give up and go buy a new phone yet. Try this, first go get a new SIM card if you don't have a brand new one from AT&T. After that is done, follow these steps in this link. These are general steps for OnePlus devices, even though the link specifies a certain handset. You're basically trying to manually enable VoLTE, which AT&T now requires for voice services to work. Here are the steps: [GUIDE] Enable VoLTE & VoWiFi on all devices NO ROOT. | XDA Forums (xda-developers.com)

You only have to follow the steps from the part where you dial *#800# and forward. You don't have to downgrade anything or download anything like it says. That's for a different device than yours.

@michael_barnard71

Again you are repeating information based on your model of phone (6T) which is on the  list for people who have a phone that is not on the list!

@michael_barnard71 to expand on what @formerlyknownas is saying — it does not matter at all that the device can actually support VoLTE, it only matters that AT&T recognizes it as such, which happens based on the IMEI of the device. So even if VoLTE is enabled in the phone, as soon as it connects to the AT&T network it'll be rejected as incompatible if the IMEI does not resolve to a model known to AT&T as supported.

I have a oneplus 6t an 7t. The 6t works fine, 7t stopped being able to make or receive calls but could do everything else just fine. Been in the store 3 times this week and on the phone for hours each day with multiple different departments. Some people were more helpful, others dissmissed my problem and said the phone will not work with their 4g hd voice network and I would have to get a new phone (THIS IS NOT NECESSARILY TRUE). I found a solution online for something else that ended up fixing the 7t looking up forums like this. I just got it working tonight when I got home. Dial *#*#4636#*#*  then Select phone info. A wierd screen pops up where you need to change the preferred network type to LTE only. Scroll up and down till you see it. After this the phone was immediately avle to make calls! No SIM swap (which I was about to do tomorrow) or reboot or anything. Try it. I hope it works!

I have a 7t which is in the list but I can't use VoLTE

@kax17  try the solution that worked for me on my oneplus 7t I posted above.

Jesussavessinners you just made my year! I did the code on my OnePlus 7t. Now I can call/text again on ATT with my 7T!!! Amazing! I don't have to use the Alcatel trash on hotspot carrying two phones (Edited per community guidelines) anymore! Thank YOU!

*#*#4636#*#*.  Is the code. Follow his instructions. This would probably work on a OnePlus 6 also? What about a 3T? I'm itching to try both.

@ananas238

Now I can call/text again on ATT with my 7T!!!

Unfortunately, that's not what's happening.  That code forces the phone to roam on T-Mobile's 3g network.

   T-Mobile is shutting off its 3g starting this month. 

   Either switch phones, or switch carriers.

@formerlyknownas 

I'm not sure what you are responding to. The OP had a OP7T Pro McLaren issue on the ATT network. All the answers were assuming the issue came from ATT's move to VOLTE and that phone not specifically whitelisted. My particular model of OP7T was also not specifically whitelisted. The code Jesussavessinners posted worked for me. I am curious as to whether or not it worked for the OP's McLaren. One day I might want to buy a OP7T Pro McL, and if that code works, then I'd love to know. Anyway, your response:

"Unfortunately, that's not what's happening.  That code forces the phone to roam on T-Mobile's 3g network.

   T-Mobile is shutting off its 3g starting this month. 

   Either switch phones, or switch carriers."

Your response seems like you posted in the wrong forum? IDK, just doesn't have anything to do with the OP, or any real replies to the issue. That code forces "the phone." Whose phone? Yours or the OP? Why are you talking about t-mobile's network in an ATT forum?