Multi-Plant MRP calculations not working correctly

Let me lay out the scenario.

• Branch A purchases SKU 123 inventory from Branch B
• Branch B is a distribution center; they source SKU 123 inventory from Branch C
• Branch C is a manufacturing center.  On the BOM for SKU 123 is a subassembly 987. The subassembly 987 inventory is normally stored in branch B.  So, Branch C sources subassembly 987 from Branch B.
• When Branch B runs out of the subassembly 987 inventory, they source the inventory from another manufacturing facility - Branch D.

I've run MRP and see the following:

• SKU 123 calculates transfer requests from Branch A to Branch B (correct)
• SKU 123 calculates transfer requests from Branch B to Branch C (correct)