I FIXED IT!!! I have been banging my head on this for what seems like forever and then I found this.
"Close out of teams completely. On Windows 10, in your search menu, search Email & Accounts. I noticed that the people that had the issue had their windows accounts missing here. I clicked Add a work or school account under the accounts used by other apps section. Then had them log in.
Teams would immediately log in without the issue. I tried logging out and restarting the PC and had them log back in and it stayed fix. Doing more testing but seems promising for me so far."