The GL distribution works this way because when the final payment on a group sales reservation is made on the same day that the reservation is checked in Altru will debit Accounts Receivable and credit Revenue. Since the programs tied to the reservation were unmapped before and are now mapped after the final payment and check in of the reservation Altru treats that revenue just like it would treat the final payment of a checked in reservation. This will cause your GL distribution to switch to debit Accounts Receivable and credit Revenue. You can avoid changes in your GL distribution by mapping any programs tied to your group sales reservation before creating and processing a group sales reservation with those programs on the itinerary