Guest user required to use Authenticator after setting up text to phone

Question

I turned on Per-User MFA for a guest user, and enabled it for one of my users (who is a B2B external). That guest user is suddenly getting a prompt that they are required to use Authenticator after setting up text to phone.

No policies are setup to require authenticator.

Can someone explain how to avoid this?

Answer 1

Understanding the diverse array of actions that may prompt Multi-Factor Authentication (MFA) for both Members and Guest users, it is paramount to utilize the sign-in logs for precise identification of the triggering event. By meticulously reviewing these logs, a comprehensive comprehension of the situation can be attained. It is important to note that access to these logs necessitates administrative privileges such as Global administrator, Security administrator, Security operator or Security Reader.