Stuck in main menu


as I already mentioned in the title I have a “bug” that I’m stuck in the main menu and can’t do anything.
The game isn’t freezed but I can’t click on anything. When I join a friend via Steam I can join the server but can’t press anything it’s like I don’t have my keyboard plugged in but I am able to open the Steam overlay. I already tried to unsubscribe every addon I’ve subscribed to before and already reinstalled Garry’s Mod 3 times now but nothing changed.

I also uploaded a video to show you how it looks like for me: