We are running 2013 CU12 Hybrid setup. Everything is working fine where on-prem users can see cloud users and cloud and can on-prem. The issue I can't seem to figure out is that O365 users that have their calendar shared with on-prem and on-prem with O365, can only see Free/Busy with time.
I have the default sharing policy in both locations set to allow "Free/Busy Time with Subject and Details" with both "All Domains" as well as "Anonymous". I also have the Organization Relationships defined so that "Free/Busy Time with Subject and Details" is allowed.
I ran the HCW to setup the hybrid environment. Test-OrganizationRelationship shows success in both environments. it just acts like it's not using the organization relationships.
If I change the default permission on my calendar to allow details, then I can see details with an account on-prem but that's not an acceptable solution.
As I said, it's the same behavior in both directions and free/busy lookups are working correctly in both directions.