Update Star Adventurer 2i:
After my colleague, Walter, fixed my issue on the bad "snap" connection, I was able to take again some images of the nightsky. First I completed the polarallignment; next I opened my app "SA Console" and connected with the mount. I selected Astro-Time Lapse and took 200 images of constellation Orion.
Postprocessing was done with Startrails and CS4.
When looking in detail, the mount is not always very accurate. But I found out I did nog fixed the altitude bold; not sure if this was the cause.
Setting
Nikon D7500 10mm f/4 ISO100 200x30s
Mount Skywatcher Star Adventurer 2i
Startrails and CS4