Conversations involving multiple participants, allowing collaboration and information sharing in Teams
Open Task Manager and look at Processes, then Background Processes. When this happens to me, there are usually several Background Processes. I kill them one by one, starting with the lowest memory use. The screen refreshes, each time and eventually all is well. Until the next time.
I remember connecting with a user, they shared their desktop and we quit. Then restarted after only a minute or so, as they were still showing as busy from the last connection. It was after that I noticed it.
It's a Microsoft issue, and they need to own it.