Order level discount on Credit Order

We use order level discounts to provide a discount for certain scenarios on SO entry.  In the case of a return we would like the discount to apply in the same way so we don't return a larger dollar amount than we were paid.

When I enter the SO, using the appropriate adjustment schedule the 'P' line (price discount line) is generated and becomes and additional Sales Order line.

When I attempt to duplicate the process on a credit order (C line type in our case) using the same customer and adjustment schedule the P line is not generated.  After some troubleshooting this appears to be related to Branch/Plant.  Returns/Credits go to BP 099, SO's to BP100.  If I change the branch on the return line to 100, I get the Price Discount, if I enter it using 099 I do not get the Price Discount.  I haven't found a setting that would related Price Discounts to a Branch plant.