cant change account for teams login

Hello,

I downloaded teams and when I start it I have to login.

It says I should enter the password for xxx@mydomain.de,  but that's not the account I want to login to.

I want to login with yyy@mydomain.de .

The login screen show a button like "login with another account". This button unfortunately doesn't work.

Currently I have no idea how to get of the xxx@mydomain.de  account.

Deinstallation of teams didn't help.

We have macOS Mojave. deleting login credentials in the keychain didn't help either.

Regards,

youngschwinn