Hello, I hope someone have some idea here. It's a bit more complex than normal, hopefully you will be able to follow me.
Domain1 with it's own Exchange server is in Hybrid mode, in the start pit of testing.
Domain2 with it's own Exchange is on-prem only granted access to free/busy through federation trust to Domain1 Exchange
Domain2 is able to see free/busy of all resources that is still on on-prem server at Domain1, but not when using room finder and choosing ressources that has been migrated to O365. However, they can see the objects if they would manually enter the @domain1.mail.onmicrosoft.com address.
However if they open the meeting room instead of using the planner they can see all content on the @domain1.com address.
So this seems to be related to federation trust free/busy sync somehow, or that domain2 is not getting the information about forwarding to the @domain1.mail.onmicrosoft.com address adn thus tries to poll against @domain1.com.
Additional information:
Domain1 and 2 have an AD trust over VPN
Domain1 and 2 use a single AD connect to sync to 1 single Azure tenant
All meeting rooms is located on Domain1 Exchange due to some weird license agreement on third party software, so Domain2 is dependant on being able to see free/busy of Domain1 to book their own meeting rooms (country separated).
Anyone got an idea of how to get free/busy to show for domain2 users on migrated domain1 resources?
Thanks