Solution : https://service.sap.com/sap/support/notes/698686 (SAP Service marketplace login required)
Key words :
symptom unexpected result, item deletion indicator, ekpo-loekz reason, filled field delete_ind, ekpo-loekz, field delete_ind, table ekpo, poitem-delete_ind, structure poitem, schedule line
Related Notes :
| 850932 | BAPI_PO_CHANGE: Problems when you delete items |
| 582221 | FAQ: BAPIs for purchase orders |