My host institution recently made a contract with Google and now we all use Google Workspace; our institutional e-mail server (Zimbra) is replaced with GMail. My full emailadress is the username, and then Google forwards one to a log-in-page of the institution via OAuth2. At the institute I use Thunderbird on WIndows, and it is able to access the new account, as expected. But here at home, where I use Linux Mint (Ubuntu/Debian based), also with Thunderbird, it doesn't work. I think the configuration is correct (it is identical to the one I use at the workplace) ''(first attached screenshot)'' But when it's supposed to open the institution's authentication window, it gets stuck in a previous step, which is the Google window that should pass/redirect to the institutional log-in window via oAuth2. ''(second attached screenshot)'' But instead, from here it goes to an unknown error, according to Google. ''(third attached screenshot)'' I don't know what functionality I possibly haven't installed or activated in Thunderbird here at home, but which is functional on Windows? Or whether some security/privacy switch of Thunderbird or Linux' firewall or whatever, is 'on' and is blocking the redirection to the third-party log-in window? How do I (in)activate or change what needs to be (in)activated or changed? Any ideas? Where can I look for this information? I scanned the questions on OAuth2 here, and none seemed related to what I experience. It's important for me that I access my work email from home. Please help.