Shipment Next Number Issue

When we creating the sales orders and/or transfer orders with the P4210 Application, have detected a problem with the Shipment Number (SHP) field; where, for each of the lines a different Shipment number is assigned. Although the orders are created with one Shipment number (Standard Logic), the Next Numbers are affected by this problem, and the system loses numbers for each sales order and lines created.

Example :

While Entering the data in P4210 detail grid like item , qty and tab down for 3 to 4 lines, system generates different shipment numbers and clicking final OK button and finding the sae order we see only 1 shipment number as below