Is every single booking synchronised with GoBright?
As long as the room has been configured within GoBright all booking information is synchronized. This is assuming that the integration has been set up correctly and the service account can access the room information.
If the room has not been configured within GoBright it will not synchronize any information. The meeting information from the room mailbox is synchronized with the platform, this includes private meetings as well. Of course, these are still marked as private within GoBright as well.