Hi Positiv,
Do you have a reference / datasheets for the USB modules you are using for the interconnection?
(Sorry my German is not quite up to ‘technical’ level, but a data sheet might help identify an issue.)
p.s. not easy to see from the photos, but I assume the board is double sided with the connecting pins repeated exactly the same on both sides of the board? Also not easy to see what the on-board switches are doing.
Assuming you are using the same USB port as in the bilder-upload photo, that is Port 1 on PilotAware Config.
Regards
Peter