Thank you for asking this question on the **Microsoft Q&A Platform. **
I agree it can be very frustrating, in a situation like this.
I found some previous answers that can guide you to fix your issue.
Why is the MS authenticator app only giving me 8-digit codes when I am always asked for a 6-digit code?
I believe you are seeing the 8-digit code on your Authenticator App because the Passwordless signing is enabled for your Microsoft account (personal Microsoft account)
I would suggest you to take a look at the steps mentioned here and see if this helps: https://social.msdn.microsoft.com/Forums/en-US/c04a9e6c-9bd0-43b2-80f9-2399242b3f92/microsoft-authenticator-app-gives-8-digit-code-instead-of-required-6-for-azure?forum=ApplicationInsights#:\~:text=You%20should%20have%20setup%20a,provide%20you%208%20digit%20codes.&text=Two%20step%20verification%20provides%206%20digit%20codes.
Hope this helps!
and Upvote, if any of the above helped, this thread can help others in the community looking for remediation for similar issues.
NOTE: To answer you as quickly as possible, please mention me in your reply.