Unapplying Prepayment from Standard Invoice when Prepayment is matched to a PO

Hello

We are implementing PO match to Prepayment functionality with R12.2.6. The issue we are having is when we Un apply the prepayment from a standard invoice, the invoice get a QTY ORD hold.

Prepayment is matched to a PO.  Is there a document or a white paper for Process changes with PO Matched to Prepayment functionality?

Thank you