Starting on September 20, 2019, my macOS 10.14.6-equipped iMac began asking me to enter the password for two Google accounts I've long had connected to the machine.
I clicked the notification bubble and it took me to the Internet Accounts area of System Preferences. Upon clicking one of the two Google accounts a dialog was presented by System Preferences that informed me I had to complete password entry for the Google account in Safari. Clicking OK opened Safari but no authorization page is every loaded.
I deleted the accounts and attempted to re-add them to the Internet Accounts settings but the problem remains. I'm stuck in a loop.
Prior to this occuring, I updated Safari on the iMac. No changes were made to either Google account by me prior to this occuring (though Google could have made changes quietly without my knowledge).
You can view the problem occuring in this screen capture video I took: https://youtu.be/wIJaBCyp_5I
Both of these Google accounts have long used 2FA if that is of any help helping me solve this problem. I would use an app-specific password here, but that doesn't appear to be an option when adding a Google account in the Internet Accounts pane of System Preferences.
How can I fix this and get these accounts re-added to macOS?