I have been logging in to Mailchimp with 2 Factor authentication using Android Google Authenticator successfully until today.
Now none of the verification codes generated by Authenticator work with Mailchimp. I get this message:
Whoa, slow down. We just can't keep up!
Google Authenticator Passcode Required
I think Authenticator is only generating verification codes for my Google Account, as the screen below the code shows my Gmail address.