Hi Faisal
You must see the Purchase Order (EBELN) and PO Line item (EBELP) populated there. So that can be used as a Clearing Criteria in OB74 i.e. EBELN and EBELP.. Can you check that?
Am not sure about this, but If you assign a Sort Key as 014, I think it will only update the PO Number, but not PO + Item Number. You may require both of them to clear the GR/IR item. So resort to FI Substitution with User Exit, if nothing helps
Ajay M