Hi SAGEX,

In Purchase Invoice, try Order selection from the left-list instead of the Receipt selection and select each PO individually. If that is not what you are looking for, you might want to open a support ticket with your local support team for further assistance. 

You need to put each Customer PO on separate deliveries in order to get separate invoices. Use the Bill of lading "Additional Deliveries" function from the right list of the BOL in order to combine the deliveries onto 1 Bill of lading. Invoicing will then invoice each delivery separate to get your desired outcome.