Inbound delivery with not correct quantity

Hi All,

We came across problem in third party drop ship scenario. Sales order created with QTY 36 and purchase requisition is generated. We have created PO with T.code ME59N. In the PO Message is sent to the vendor through EDI with out put type 850.

Now vendor is sending the Advance shipping notification (ASN).When we receive the IDOC in our system inbound delivery is created. At this time purchase order history is not updated

We will make GR with respective to the inbound delivery. When we are posting GR the quantity is showing in different line items with 2 each and total quantity only posting as 10

We are unable to analyze why the system is taking qty 2 instead of taking complete qty 36.

Please help as it is high priority requirement.

Thanks&regards,

Chand