Change requests that meet the CAB meeting conditions, aren't being associated with the CAB meeting.
The change requests that aren't being attached were previously associated with other CAB meetings. But no decision was made on them so the change request is in a state of pending and until a decision is made on them in the previous CAB meeting they won't associate with any new CAB meetings. Search for the missing change request on the cab_agenda_item table.
Creating a Business Rule that when a CAB meeting is either canceled or has ended, will change any change request state associated with it that are still in a state of pending to no decision.