Demand Management - System Rejected

I am having trouble finding where to set whether an inbound line item is rejected by the system.

Currently there are some customers that when the inbound item number does not match the PO/order is held in the Demand Entry screen ( this is what we would prefer), but there are some customers that if they have an incorrect part number, then “System Rejected” shows up in the Demand Entry.

I have compared the Customer Display- Demand and Customer Display - Documents screens and they seem to be setup the same way:
Unit Price Difference (checked). action = stop
Check for Part ( checked ). action = stop

Thank you