I haven't loggued in to my matrix account in a long time. I didn't remember which way i used, so i used my email adress, which created a new account. Trying to log out and in again didn't showed me the other options such as login with mozilla (sso), so i deleted that new account (@sebbu2:mozilla.org). Meanwhile, I'm not sure i even am loggued out properly, since i get the same message when i try the original account (@sebbu:mozilla.org) that used mozilla sso.