Unable to update Withholding Tax DFF value in Cloud Payables

Summary:

We are loading Payables invoices from a legacy system into Oracle Cloud Applications. Some invoice lines have AWT (Withholding Tax). When these invoices are validated, Oracle automatically creates a new Withholding Tax invoice with a new invoice number.

Our requirement is to update the original legacy invoice number in a DFF on the newly created Withholding Tax invoice.

When we try to update the DFF using the REST API with a PATCH request, we receive the following error:

AP-810780:
You can't perform this operation because the invoice type isn't Standard, Credit memo, Debit memo, or Prepayment.

Payload used:

https://iavwme-test.fa.ocs.oraclecloud.com/fscmRestApi/resources/11.13.18.05/invoices/5002/child/invoiceDff/5002