Have you walked through the troubleshooter?
on-prem users are not able to view the free/busy of cloud users in hybrid setup
Pradeep Kabbur
40
Reputation points
We are setting up a hybrid Exchange setup from Exchange 2029. We are trying to test the free/busy of migrated users mailbox after mailbox is migrated to Exchange online.
We have issue seeing free/busy status of Exchange online users from on-premises (on premise users). once we migrate them to Exchange Online.
We did troubleshoot by checking - Autodiscovery, Federation test, organization relationship, target sharing