So Att S22 Ultra now uses a custom google messages app as default, but RCS is not working with all people who use Google messages. Example my brother is also on Att and he has an Att version of the Fold 3. The default messaging app on that one is Samsungs app but he is using the Google messaging app from the playstore. Messages sent and received from him are SMS not RCS. I have another brother that has a t-mobile s10 and my messages with him are RCS and I think he is even using the default Samsung app. I know I'm not the only one but no one is talking about this.