What I see is that you are using KOMK-WERKS
KOMK is a header structure, I think you should use KOMP-WERKS to have the plant from your item line.
As it is an INTERcompany order it has a vendor in the header, an INTRAcompany order would have a plant in the header.
Further I see that the product hierarchy fields are empty, you are using PRODH structure, PRODH is a field from MVKE material master sales view, PRDHA is the field from material master basic data view.
I cannot imagine that a SAP purchase order can know about sales org specific fields.
As all those fields are empty (initial) when you access the conditions, it cannot find any.