HD Voice Compatibility With Samsung Galaxy S20 FE (SM-G780G)
I have a Samsung Galaxy S20 FE (SM-G780G) that appears to support HD Voice, but AT&T's database says that it doesn't, and thus service to the phone/SIM keeps getting disabled. I have performed testing and found that the phone appears to support LTE calling, even with AT&T service. During the the following tests I use an AT&T prepaid SIM card and an AT&T postpaid SIM card that my work pays for through their account.
Test 1 - SM-G780G with prepaid SIM card, Galaxy S10e with postpaid SIM card : SM-G780G shows H+ during a call. Galaxy S10e shows LTE during the call.
Test 2 - SM-G780G with postpaid SIM card, Galaxy S10e with prepaid SIM card: SM-G780G shows LTE during call, S10e shows LTE during call. SM-G780G received a text message saying that the phone is not compatible, but was still able to place an LTE call.
Test 3 - SM-G780G with prepaid SIM card, Galaxy S10e with postpaid SIM card: SM-G780G shows LTE during call.
Test 4 (roughly 5 minutes after Test 3) - SM-G780G with prepaid SIM card, calling a third phone number now: SM-G780G shows H+ during the call.
Test 5 (roughly 5 minutes after Test 4) - SM-G780G/prepaid SIM card is now disabled and calls go directly to AT&T support.
It appears to me that the phone fully supports HD Voice, but that AT&T has it incorrectly labelled as non-HD Voice compatible. Am I able to work with AT&T to allow the phone to place HD Voice calls, seeing as my tests show that the phone is capable? Am I able to mark the SIM card/phone as HD Voice compatible (like an override), and then if calls don't work after 3G is shut down (even though my tests show that it supports HD Voice), then that just becomes a problem for me to resolve at that time?