Might be worth moving to iCloud Keychain 2FA now. Since you're all in for Apple it would work. Of course, I use 1Password but get how someone wouldn't want to pay for it when the Google Auth app is free.
Have you looked at hardware keys?
I know none of this helps your current issue, but it does seem that you aren't alone.
Louis L'Amour, “To make democracy work, we must be a nation of participants, not simply observers.
One who does not vote has no right to complain.”
Visit our archived Minecraft world! | Maybe someday I'll proof read, until then deal with it.