So, I was able to solve this by re-establishing the account in the Authenticator app. It was not easy, there are a couple of account recovery processes that fork pretty severely on MSFT's support site and it took me three tries to find the right way to do it. I can't remember the exact options available, I should have written it down so that I could share it with everyone. I'm sorry about that! But there is a way to work through the recovery process such that you get an opportunity to enter the OTP code from the Authenticator app - this still works despite the error message during push notifications or number-matching. Once authenticated that way, I removed the account from the Authenticator app, then went into the account security settings, turned off 2-step verification, and removed the Authenticator app as an authentication option. Then I added the Authenticator app back using the normal QR-code scanning process, then turned 2-step verification back on. I was then able to log out and log back in using number-matching with the Authenticator app, and it worked fine. Again, I'm sorry for not writing down the exact steps from the account recovery process to trigger the option to enter the OTP code, but it does still work even with the other errors present.