Clear the Teams cache.
1. In the bottom right corner of the task bar, click the ^ arrow and force quit Teams by right clicking on the Teams icon and choosing Quit Teams.
2. With Teams fully closed, open Windows explorer and type C:\Users\%username%\AppData\Local\Packages\MSTeams_8wekyb3d8bbwe in the search box.
3. Double click on the folder that appears.
4. Delete all files and folders in this directory.
5. Reopen Teams.