Customer Down payment - Final invoice with zero amount

[sunr1]

Hi

I have made a Sales order/Down payment request with a billing plan like the below:

I have created billing document (VF01) and clear down payment request (F-29) and works fine. However when I create the billing document for the final invoice the amount is 0 EUR.

I have read blogs about this but havn't found a clear answer yet, so therefore my blog post.

Please help

Thanks.