I was prompted on tasks.microsoft.com that my password expires and to change it. I changed it. This caused Teams to require to sign back in with the new password. Upon clicking "Sign In" on the desktop app, the app closed, relaunched and told me again to sign back in with my new password. Clicking again "sign in" caused the app to close and restart back on the previous screen. I looped this about 15 times. Sign out from start menu did nothing. Teams app while the "sign back in" screen is shown is unusable. Had to reinstall.