Two brand new S20 Ultra has Advanced Messaging turned on but it stopped functioning on August 4th.
I just chatted with AT&T for this issue with our brand new S20 Ultra phones. We purchased the phones on 7/29 from an AT&T store. The Advanced Messaging worked for literally two weeks and then, although turned on, stopped working. The chat is no longer showing delivered, or read, you can't see when the other is typing. The transcription feature on the Visual Voicemail doesn't work either (though that never has).
AT&T online support person (on 8/10) claimed they ordered a push from the manufacturer (Samsung) to fix our phones. We were to receive the fix within 6 hours and that will correct the issue. No push was ever received (unless there is no sign of the push). The phones still aren't functioning properly. They are $1400 each!!!!!
Ready to return these phones.