I found the Solution...very simple, just delete the wireguardconfig that looks not very healthy in the flash drive.
As you can see in the picture it does not look as a config should look like.
As i explained first i forgott to extract the vpn config from the zipfile and uploaded the complete zipfile.
So i think wireguard somehow tryied to build out of bits and bytes from the zip a vpn configuration and that in the picture is the result.
My other VPNs were still funktional but i could not go to the adminpage of wireguard in the webgui. I think the webgui just coud not present those kind of symbols.
Strange that there is no securitylayer that prevents somebody uploading a zipfile but thats how it is.
I hope - if somebody does the same mistake in the future like i did now - this post will help.
so simple Solution. The first i9 i had was not of good qualitiy. With the second i9 i got everything worked fine - except sometimes when the cpu got a big spike.
Then i realised my PSU is to small - bought a oversized one 1200W Titanium and now everything works, nothing is crashing.
