Reset Users Multiform authentication / Microsoft Authentication App.
- Login to Entra https://entra.microsoft.com/
- On the left hand menu goto Users à All Users
- Now find and select the user requesting the Authenticator App Rest
- Now, on the users menu select Authentication Methods
- Then, on the top menu bar click Require re-register multifactor authentication
- Now if the end user logs back in on a Office 365 web page they will be given the chance to enrol the Microsoft Authentication App again.