We're using BAPI BAPI_PO_CREATE1 to create a PO with reference to a conract.
On that contract, we assign a MoT Group - a MoT value that corresponds to several MoT values.
For instance, MoT 91 allows MoT 07, 08, and 09.
When we pass a value to the OIC_MOT field of 07, the PO is trying to create using MoT = 91.
We are using the ExtensionIn structure and are marking the appropriate OIC_MOT = 'X' in the ExtenionInX structure.