Print Receivable Transaction Program sending invoice to all contacts of an account

Summary:

Print Receivable Transaction Program sending invoice to all contacts of an account despite invoice having a single contact associated.

We have an invoice in our system sent to all the contacts of a customer account despite invoice having an actual valid contact associated.

We use print receivable transaction's customized version however, the program never sends invoice to all contacts if the invoice has a valid contact on it - need oracle's help to troubleshoot and answer a customer facing issue this has caused in our company.