Hi,
In this case, you can try to Repair office app.
If it doesn't work, I would recommend that you contact your school IT Admin directly so that they may reset your MFA settings.
Finaly, if the issue still persists, please ask your IT Admin to contact the Microsoft support team.
A technical support engineer can perform a remote session to investigate the situation, verify the backend configurations, and run any necessary synchronization tools to resolve the problem. If the issue requires further attention, they can escalate it to a specialized team for deeper analysis.
As forum moderators, we don’t have access to the detailed logs or backend systems needed to troubleshoot this effectively due to privacy and security constraints. For that reason, the most efficient solution would be to contact Microsoft’s support team directly. Here’s what your Office 365 Global Admin should do next: Submit a Service Request: The Global Admin should create a service request with Microsoft support to get advanced technical assistance and diagnostics. For detailed instructions on how to get support, please refer to Get support - Microsoft 365 admin.
I sincerely hope this is useful.
If you want any further information or support, please let me know!
Looking forward to hearing from you.
Best Regards,
Kai Vo - MSFT | Microsoft Community Support Specialist