One of my Microsoft Account IDs is setup for two-factor. All was working at some point via an Authenticator app.

Go go login today to register a new device to run the Authenticator. Says I haven't logged in recently, and asks for the second factor.

Have tried multiple times using Authenticator token for old device, birth year, and a code sent via email. Every one I've tried ends at:

There's a temporary problem with the service. Please try again. If you continue to get this message, try again later."

This has been going on for over six hours for this account. My other two-factor account is working fine. (Was challenged for the second factor on that account as recently as last night.)

Wassup with this? What's the workaround to get normal sign-in access restored?