PO Line not showing for Receiver

I have a PO that contains 10 lines (sourced from a requisition). A PO line was manually added afterwards (making the PO have 11 lines). This 11 line of the PO does not show for the Receiver. The Receiving page indicates that the User has 11 lines to receive, but the grid only shows 10. I have ruled out, all the usual issues. I.e. Does the receiver have the correct role, is the ship to location valid etc. Has anybody every experienced this before?