I don't have access to MOS. Can you share the idea behind that link?
Following may be the reason. It may one of them.
1. Wrong receiving organization is being used to receive the po in
2. Incorrect ship to org was utilized on the PO and wrong organization was being utilized to perform the receiving, thus the purchase order would never display in the List Of Values due to being in the wrong receiving organization.
3. The PO Routing NOT set to Direct Delivery
4. The issue occurs because the buyer who created the PO (i.e the agent_id of PO_headers_all ) has been inactivated.
5. The buyer has an assignment linked to an incorrect organization (ie he is assigned to an organization linked to another Operating unit)
6. PO is not in an Approved status.