Invoice Lines not available for Prepayment Invoice against Complex PO

Summary:

Hi Team,

We are having a scenario where client wants to capture milestones in a purchase order for which they are using complex purchase order and thus creating multiple schedules.

Now when we try to create the invoice against the complex purchase order with invoice type as 'Standard' and try to match invoice lines, the purchase order lines are appearing. But as soon as the invoice type changes to 'Prepayment' and when trying to match invoice lines, the purchase order lines does not appear.

Pls find below the client expectations regarding PO-Supplier Advances functionality as there construction entity and their core business are based on prepayment based on milestone.