Hello Bob,
Greetings for the day! I’m an Independent Advisor and Microsoft user like you. Thanks for posting the query here at this forum.
I understand your concern as there is an issue with accessing Authenticator app.
Could you please attach a screenshot of the error message? If there are any cache issue, deleting and reinstalling the app would help. Unfortunately it doesn't help in your case.
If you have issues with changing the MFA option, could you please try below steps to disable or remove authenticator app temporarily? You can verify using mobile or email option until this issue is resolved.
- Go to Security settings and sign in with your Microsoft account. http://go.microsoft.com/fwlink/?LinkId=529561
- Under the Two-step verification section, choose Set up two-step verification to turn it on, or choose Turn off two-step verification to turn it off.
- Follow the instructions.
https://support.microsoft.com/account-billing/b1a56fc2-caf3-a5a1-f7e3-4309e99987ca
Hope this information helps. Please feel free to get back if you have any questions.
Thank you! Ravikumar Help the next person who has this issue by indicating if this reply solved your problem. Click Yes or No below.