Hi Wanchaloem, the reason of the two invoices is the one you found. I have to change the field in customizing, but this will be possible from May 4th, because development system is closed. Are you simulating a real business situation or you are trying the different possibilities offered by the system?
Yes, I'm trying to simulating the real business event in the PEI100, you can see Sales order 1351948 in PEI100 system