Sales Order - Job Reservation Issue

Hi Experts/Gurus,

We have EBS R12.1.3.

We are going to make a link of Discrete Job and Sales Order and want to make a Reservation of Sales Order to corresponding Job Order.

For the same we are populating MTL_RESERVATIONS_INTERFACE and running the concurrent request RESERVATION INTERFACE MANAGER.  For some of the case it is working fine means it's showing reservation of SO & JOB on Inventory Reservation from and also showing sales order ('SO Number.Order Type.ORDER ENTRY') on discrete job form.

But in some of the cases the reservation done perfectly and showing SO-JOB reservation also on Reservation from but the link of SO ('SO Number.Order Type.ORDER ENTRY') is not showing on discrete job form.