Purchase Order and Stock requirement List

Hi Experts,

I have this scenario.We created a production order PO#12345, and we convert it to subcontracting Pur Ord PO#67890, But we checked that one of the component is out of stock, so we changed the BOM of Production order and the Purchase Order.We just replaced the component.

component ABC to component DEF

The problem is when we checked the stock/requirement list of the component DEF, it becomes 2 requirements with different provision number.The first provision number is tag to production order 12345 then the other provision number is tag to Pur Ord 67890. I'm expecting that since PO12345 and Pur Ord 67890 is linked or came from same requirement it will just show 1 requirement for the component DEF.

Thanks in advance