Solution : https://service.sap.com/sap/support/notes/372819 (SAP Service marketplace login required)
Key words : 
additional key words cor1, automatic batch number assignment, source code corrections, batch manually, item number, process order, production order, goods receipt, user exits, order item
Related Notes : 
       
| 440857 | Problems with batches for order items | 
| 382782 | Order item is not transferred to X_BNCOM | 
| 81017 | COR1/COR2: Order number is empty in bncom |