Hello @Sepp_Schembera, welcome to the Nextcloud community! 
I’m wondering why you try to post link at all. Don’t forget proper formating - e.g. post config files as “code” so there URL in the post. Review valuable beginner topics e.g.
and try to explain your problem in a way others can understand it - AFAIK Rustdesk is a remote control application I don’t really get how you expect it could improve your file transfer issue.