Solution : https://service.sap.com/sap/support/notes/333788 (SAP Service marketplace login required)
Key words : 
additional key words kzvbr, individual purchase order items, single account assignment, purchase order, confirmed quantity, implement note 321021, schedule line, program error, solution implement, attached correction
Related Notes : 
       
| 332533 | Data inconsistency in CO after ship-to party change |