Group Texting issue

On Sunday I purchased a new S20 and from the moment the phone was up and running I have been having an issue with my MMS messaging. It's not working AT ALL. I currently have 150 messages waiting for download. I have tried everything soft/hard reset, clear phone cache, clear app cache, reset network. Yes my settings are correct for receiving MMS in the factory app as well as several 3rd party apps. I DID NOT have this issue with my S8, why am I having this issue with a brand new supposed to be state of the art phone on a basic use of the phone. I have been able to chat with SamSung, Google and they have said its not an issue on their end. I saw a Reddit that is saying it is AT&T specifically. Is this being rectified??? again this is a basic function of the phone that should be working Please Advise as I am new to ATT and in 20 years being with Sprint never had this issue