Deletion indicator set on Purchase requisition automatically at PO create

Hi Experts,

I am looking at an issue where the system sets the deletion indicator automatically once requisition is released and PO created against it

I tested by creating a requisition, releasing it through ME54N and then creating a purchase order by copying it......once PO is created the requisition has a deletion indicator

I have tested requisitions with account assignment category as Cost center & work order and in both cases I see this issue

Can you throw some light what might be causing this?

Thanks