Troubleshooting Multi-Factor Authentication on Office 365

Manage MFA user settings

1. You must be an Office 365 global admin to do these steps.  Go to the Office 365 admin center.
    
2. Go to Users > Active users.
    
3. Choose More > multifactor authentication setup. If you don't see the More option, then you aren't a global admin for your subscription.
    
4. On the multi-factor authentication page, select the check box next to the people you want to manage.
    
5. On the right, under quick steps, choose Manage user settings.
    
6. In the Manage user settings dialog box, select one or more of the following options:

• Require selected users to provide contact methods again
• Delete all existing app passwords generated by the selected users
• Restore multi-factor authentication on all remembered devices - Any devices that have had the “Don’t ask again for 60 days” checkbox set will now need to authenticate via MFA again.