I'm one of the many experiencing problems since the 3G shutdown. Apologies if this has been asked and answered, but I have searched and not come across anyone with this specific issue.

My phone is a ZTE Axon 7 mini. Following the shutdown, my phone lost the ability to do voice calls, but sms, mms, and data all still worked fine (as many others have described). Airvoice sent me a replacement SIM card, which had a preloaded ATT Nextgenphone APN on it. This immediately allowed me to make voice calls and sms, but prevented any data connections or mms.

When I added the standard Airvoice att.mvno APN, my phone behaves just as it did following the shutdown: no voice calls, but sms, mms, and data all work fine. None of the 3-4 Airvoice reps I have talked to on the phone seem to have any awareness whatsoever of the nxtgenphone APN, and all assure me that the att.mvno APN should work.

I tried creating a third APN combining the Airvoice mms (http://mmsc.cinclular.com) and the nxtgenphone settings (proxy and port left blank), but this behaves exactly as the preset ATT nextgenphone APN (voice and sms, no mms or data).

My current workaround is to leave it on the nxtgenphone APN in order to make and receive calls, and then switch to the att.mvno APN when I need to use data, or when I get an mms message that I can see is hung up and unable to download. This is of course not an ideal situation.

I've read others posting about AT&T maybe not wanting my unapproved device making calls on their network, but this does not seem to be the issue I am having since I can make the calls on one APN, but not the other.

Any ideas or suggestions to try?