How do I Reset my Authenticator app?

For Education account the user account is managed by the school IT administrator. To reset the Authenticator app, you need to contact the IT admin. In your situation, you are trying to use the authenticator on a new phone. For security reasons, it cannot be performed as the MFA is still installed in your previous device.

How does the Microsoft Authenticator app work?

The Microsoft Authenticator app backs up your account credentials and related app settings, such as the order of your accounts, to the cloud. You can then use the app to recover your information on a new device, potentially avoiding getting locked out or having to recreate accounts.

How do I delete a work/school account from the authenticator app?

Open the authenticator app on your mobile device, select Edit accounts, and then delete your work or school account from the authenticator app. Your account is completely removed from the authenticator app for two-factor verification and password reset requests.

Does adding authenticator remove the app from my old device?

A: Adding Authenticator to your new device doesn't automatically remove the app from your old device. Even deleting the app from your old device isn't enough. You must both delete the app from your old device AND tell Microsoft or your organization to forget and unregister the old device.