After creating a down payment based Invoice for a Sales Order, the second Invoice is a refund, not the balance. Why?
For an invoice of value 7000USD I have created a DownPayment of 2000USD from sales order. Then I validate the invoice and register payment. Next installment I want to generate invoice for the balance 5000USD , so I create Invoice from Sales order I choose the - Invoiceable lines (deduct down payments). This should ideally create an invoice for 5000 USD after deducting 2000 USD as downpayment. Here is where I have problem, this creates a refund for 2000 USD instead of Invoice for balance.
Please advice where is the problem?