Mi phone is 4G and support HD Voice. Why it will no longer work with AT&T after 3G network shutdown?
I currently have a Xiaomi Mi 8 SE. Is a 4G device, and does support HD Voice and VoLTE. However, it is not on the list of phones which will still work on ATT network after 3G shutdown in February 2022 (no Xiaomi phone is listed there) https://www.att.com/idpassets/images/support/wireless/Devices-Working-on-ATT-Network.pdf. Why is that? I've been told that only phones manufactured in the US will be compatible after 3G network shutdown. Nevertheless, I find many models manufactured in China on that list, and am unable to find any related info in internet (only see that 3G phones will become obsolete, which makes sense to me).
I understand AT&T tries to make business out of this, but would like to know if this is a real requirement, and if so, whether it is the same requirement for the different providers in US (T-Mobile, Sprint, etc).
If my phone will still be ok in a different network I will simply switch the provider and keep my phone as it still works to me...