2FA problems - "Could not validate OTP" error message

I am completely bewildered by this 2FA stuff. At the prompt where it asks to enter the six digit code from authenticator app, both the mobile app and website keep giving me a “Could not validate OTP” error message. I’m using the Google Authenticator app.

I cannot get to the screen where it asks to scan a barcode, and are having no luck trying to disable 2FA.
I don’t even remember getting any one-time recovery codes.

Can anyone give any pointers?