Problem in MIRO agains BILL OF LADING & INBOUND DELIVERY

Hi GURUS / EXPERTS,

I am using INBOUND DELIVERY AGAINST PO (VL31N) & POST GOODS RECEIPT,where I mention the BILL OF LADING in SHIPMENT at Header data. After that I use MIRO, during MIRO, i reference the bill of lading number Which is mentioned in the inbound delivery. But, only the freight and other charges vendors are pulled onto MIRO. Main Vendor (i.e. Material Supplier) is not appearing here.

Please suggest.

Thanks in advance.

DSC