KevinTheJedi
Yes, I have opened the case with Microsoft, but they are point back to osTicket
strange, but I have found one post related to hybrid setup, maybe that's the issue, we are running this setup:
https://blog.thenetw.org/2019/05/13/using-client_credentials-with-microsoft-graph-in-hybrid-exchange-setup/
ActAsPermissions and set it to AppOnlyPermissions