Google Authentication in Internet Accounts
I have Monterey (12.4) and have a similar problem to others, namely Gmail accounts not working with Apple Mail..
However, during one of the proposed solutions of deleting and then adding back a Gmail account, I discovered that in System Preferences / Internet Accounts, I can't do that. When I start to add the account by hitting Google, it gives me the "Google requires completing authentication in your web browser" and then when I try to "Open Browser" I get the Authentication Failed message.
NOTE that I NEVER GOT to point of specifying an account to be "authenticated", Internet Accounts simply did not work with Google at all.
iMac 27″, macOS 12.4