Welcome to our forum!
It looks like your problem is related to Outlook Authenticator on your mobile device, please kindly understand that the Outlook tag here we mainly focus on general issues about Outlook desktop client. In order to better solve your problem, it's suggested to post your issue on this dedicated forum for Outlook for Mobile for more professional help.
Here are a few steps you can try to resolve the issue:
Check your settings: Make sure the Authenticator app is updated to the latest version. Go to the app's settings and ensure that app updates are turned on.
Switch networks: If you're using mobile data, try switching to Wi-Fi, or vice versa. Sometimes network changes can help.
Disable battery optimization: Go to the app's settings and turn off battery optimization for better sync performance.
Re-add your account: Go to myaccount.microsoft.com and under security and info, manage login verification methods. Delete Microsoft Authenticator as an option and then re-add it.
Contact your IT admin: If none of the above step's work, you may need to contact your university's IT admin to help you disable and re-enable Multi-factor authentication for your account.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.