I've discovered a strange behavior. I've generated a list which I customized a lot among other things using a .js file which I added to the JSLink field of the web part.
The list is working perfectly fine and all the JavaScript stuff working as expected.
I went to the list settings and save the list template using Save list as template and checked the "Include Content" box.
Now I'm able to add this list via the Site Contents >> add an app function to other sites. The list will be imported and is working as expected including all the JavaScript functions.
BUT when I go to an site and choose the "edit page" option and add this list as a webpart, the JavaScript part is not working anymore due to under "edit web part" the JSLink property is not set anymore.
Is there any way to add the "imported" list as a web part including all properties?
PS: When I export the list as a web part, the list does not contain any content anymore. So this isn't an option either.