Hello @josephs484 ,
When a user logs in using their own login credentials for the first time (after an account has been activated for MFA), it will prompt them to setup their own MFA method. If another user's login was setup prior to the big MFA update a couple months ago, it's likely that their credentials are still setup with your phone number associated for their MFA. Either you or they will need to call our general support, so we can securely assist in getting this user's MFA preferences updated.
For more info regarding MFA, make sure to check out our Community's FAQ on the subject.
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