I've tried seeing if anyone has had this issue but i'm not finding a thread. TL;DR. Gmail authentication screen pops up but does not allow authentication. It deletes your email input and prompts for your email again. FULL EXPLANATION: Thunderbird 101.0b4 and my gmail account was previsiously configured and working properly. My Gmail 2FA/MFA was in place before I set up my gmail in Thunderbird again. I am not sure at what point it stopped working. I don't remember what possible change could have triggered this on my end. Nor do I know if it happened with it specific upgrade to Thunderbird. For the last few weeks, I occasionally open Thunderbird to access my gmail and it attempts to fetch my email from google but it's unable to authenticate. A Gmail authentication screen pops up but does not allow authentication. I input my email address I hit enter. It deletes my email input and prompts for my email again. It gives no error message and does not change screens. It does not prompt for the password. Nothing. I'm not seeing any security issues presented with Google. So I'm not sure what's blocking this.