AT&T tells me my Samsung S8+ is no longer compatible with their network

On March 4, 2022, my Samsung S8+ Could no longer accept or make a voice call.  Data services were okay.  After going to their AT&T store, they informed me that we would have to purchase an AT&T branded phone because the unlocked phone would no longer work on their network.

I believe this is totally bogus.  AT&T’s own document shows the Samsungs S8+ as fully supported including advanced messaging.

I called technical support and they reiterated that message and said they tried to “update” the SIM and the phone was incompatible and that we would have to buy a locked AT&T phone.  

I pressed them on an official document that stated that AT&T would no longer support that and they said there was none.  Additionally, they said all of the calls they have been getting on this issue were unlocked phones.

So apparently AT&T changed something on their network which broke the voice capability for the Samsung S8+.  I have several phones, and placed the same SIM into a brand new Pixel 3XL and it is working fine.

If what the store and tech support said is true, AT&T has really done their customer base a dis-service by treating them in this manner and telling them they have to buy an AT&T locked phone.  

I intend to contact my State Rep on Monday and complain as well as file a Consumer complaint.  They were very happy to place my Samsung S8+ on their network 2 months ago and now they say it is incompatible.  this really smells like an attempt to force unlocked phone users to purchase an AT&T locked phone.