enekoas
Yes, new plugin build, same number. We only change the version of plugins on major changes.
Have you checked all logs (general server logs, webserver error logs, PHP error logs, MySQL/MariaDB error logs, osTicket System Logs, Browser Console logs, etc.) for any related errors?
I'm wondering if the information your system gets back from the auth attempt from MS is not matching the User's Agent's information. If you sign in as a User does it work (just not with an Agent)? If so that indicates issues with matching account info (email/username) with the Agent's profile information. Make sure these match exactly what's in the IdP.
Cheers.