Kirby Backend unusable after domain migration

I have a Website that was moved from the Prod Domain to a Dev domain.
When logging into the Backend No Icons (font-awesome) are displayed, modals cant be opened (like uploading files) or editing structure fields.

No Code was changed when moving from prod to dev - In my config.php there is no c::set(‘url’) set, I havent modified the core or anything.
In the Webinspector Tool Console I get the errors “$ is not defined”. So I guess it has to be a problem with the default integration of jquery in the Backend.

Is there any way to fix this?

Looks like jQuery is not loaded for some reason. If you check the network tab, what do you see there regarding jQuery?

I am using Kirby 2.5.12. This is what is beeing loaded in the Backend:

The only thing that looks irregular is the inject.js file. Where does that come from? Is that some sort of browser extension being loaded?

Yes it comes from the Extension “Wappalyzer” but even when disabled I get the same problem.
In other Kirby installations I don’t this problem…