Issue with Processing Returns in a Single FBDI Loadsheet

I am attempting to create a return on a purchase order receipt using an FBDI loadsheet. I have created two lines in the RCV_TRANSACTIONS_INTERFACE tab. The first line is "return to receiving" and the second line is "return to vendor." When I process these in a single loadsheet, I receive the following error message: "The receiving transaction interface contains values for both the Parent Interface Transaction ID 5975623 and the Parent Transaction ID {PAR_TRX_ID}."

Is it simply not possible to process this in one loadsheet? When I process the lines in two separate loadsheets, it works. However, when I process them in one loadsheet, only the "Return to Receiving" line is processed. Can someone assist with this issue?