Same problem here - MS Teams on my phone keeps refreshing. Has been doing that for the past 3 days. Have cleared the cache, same. Have reinstalled, same.
Additionally, when I open MS Teams on my PC, my Outlook Exchange account logs off and can't enter the password not even after turning off both apps. Outlook is logging on to my Exchange account only after restarting the computer and not opening up MS Teams.
Not sure what Microsoft is doing, but it's clearly a bigger problem than a simple cache. I've paid good money to have this Outlook version on my home computer, so if it's not fixed will make a complaint. I am forced to work from home, and can't do this properly with all these apps fighting each other...