
Seems that the login token is cached for a while and later a new (automated) login fails because of expired token/credentials. In my opinion it could be related to the 2FA, which is enabled for my account.

I have no idea how long it works before the error occurs, maybe it´s a few hours or a few days.

The problem seems only to occur with Vivaldi, while with Firefox, Chrome, Edge it seems to work fine. Later, after clicking the extension button, not the usual menu is shown, but it pops up for a millisecond and after that I´m logged out and the extensions login form requires a new authentication. After providing login data including 2-Factor-TOTP, the extension is logged in and works fine.
