Yup, got burned by this. I had a POCO X3 (4G LTE but no VoLTE) which I'd still be using today had AT&T not labeled it as a 3G phone. Even just attempting to use

Yup, got burned by this. I had a POCO X3 (4G LTE but no VoLTE) which I'd still be using today had AT&T not labeled it as a 3G phone. Even just attempting to use it with my SIM card now automatically deactivates my plan. Now they have a phone whitelist restricted to (mostly) mainstream brands...