Direct Delivery Workbench confirming PO's


When I try to confirm a PO and generate a full product receipt in the Direct delivery workbench, it generates or ties past POs to the DD PO you are trying to confirm and errors out. 

And when i  delete the LD and LF PO's and try to generate the full product receipt again, it just finds more PO's to tie up and generates a different error.

Any idea why this might be happening? Thanks