Shipment number clearing when picking for WMS

We are running JDE 9.2.7.2.

We are seeing an issue where when we use P4617 to confirm the pick confirmation, we have times where the shipment number clears or goes to 99. A while back we found that what was happening is that our promised delivery dates did not match in P4210 and P4915. What we think is happening is that when a CSR changes a pick date or request date or any other date, that does not update P4915 dates which cuases the issue. Do you know how or if we change a date in P4210 it will automatically update the