Solution : https://service.sap.com/sap/support/notes/434616 (SAP Service marketplace login required)
Key words : 
target cost calculation displays incorrect values, afpo-weunb = 'x', nonvaluated delivery, production order, sales order, quantity delivered, table coepl, terms mb31, fabe interface, cosl reason
Related Notes : 
       
| 492552 | Posting error CO docs w/ goods movements fr confirmation |