My Permalinks are too long, they contain the URL 2 times... How can I fix it?

I just moved my site to another host.

The site is online and wrks, but it seems that something is weired with the Permalinks.
Fortunately I have installed a plugin ("Permalink Finder") that redirects wrong Permalinks. I saw that there are a lot of Permalinks that needed to be fixed by the plugin... >

For example, the "original" URL
is now

My host (who did the site migration) says that they "reset the permalink rules" and that everything is fine this way. But my Permalink Plugin keeps to show me fixed Permalinks.

Would anybody be able to tell me where the problem is?
Please :slight_smile: