Hello Henry,
My name is Oluwatosin, and I’ll be more than happy to help you with your query." This is a user-to-user community forum. We do not have access to your account.
I'm sorry to hear that you're having trouble signing in using the authenticator app.
Since the account is a school account, the issue might only be resolved by your institution's Helpdesk.
However, you can try out the troubleshooting steps below:
Check you run the latest version of Authenticator. Tap Settings and make sure App updates are turned on, and turn on VPN if enabled.
Try using an Incognito browser session on your device.
Also, try signing into: https://mysignins.microsoft.com/security-info to replace the security information.
However, if sign-in is not possible, contact your help desk to make sure your account is not blocked by any policies and reset your account to re-register authentication.
I hope this helps! Let me know if you have any questions.
Give back to the Community. Help the next person who has this issue by indicating if this reply solved your problem. Click Yes or No below.
Best regards, Oluwatosin.