Seems that TB V91.80 changed my gmail settings to Oauth2. While I would like to use OAuth2 to log in to my gmail, this has simply never worked. The window that now opens says that my account could not be found, any attempt to find it brings up something regarding cookies which I have turned off globally. I enabled cookies (as an exception) for google.com and accounts.google.com., but no luck. Logging in to my gmail from Firefox works fine.