In Microsoft Office 365 Dedicated/ITAR vNext, you cannot see the room capacity when you 're booking rooms that are still in legacy during coexistence.
This behavior was investigated and identified as a "by design" cross-forest scenario. By default, the msExchResourceCapacity value is not written-back from legacy-dedicated to on-premises. Therefore, the value is not written from on-premises to cloud by AAD Connect.
This issue is resolved after the room is migrated to vNext. To work around this issue, add the capacity to the display name of the room.
Note Adding the value directly to the on-premises msExchResourceCapacity value does not resolve the issue.
Article ID: 4025290 - Last Review: 2017, ജൂൺ 13 - Revision: 8