Panel Light Problems

Well hello once again and yes, I have another Problem that is pretty much annoying.

For some reason Panel Lights don't work anymore in some Aircrafts (Like the 737, the Cessna, Beechcraft and some others, but do work in the Extra 300S). When I hit the Button (or L) for Panel lights nothing happens but it shows me its loading something (you know the little microsoft mouse cursor thing), the Panel and the entire Cockpit remains dark though. I figured out that Taxi Lights and some others work, but the most important thing, the cockpit light dont 😞 .

Weird thing is, when I start flying at night, it works...

Problem occurs in Singleplayer as well as in Multiplayer.

In the realism Settings the box "Pilot controls Lights" is checked and i tried different aircraft skins already although Im sure this is not the problem.

And yeah, I've tried searching on here for a solution but as far as i found something it didnt really help yet :/.

So if anybody has a solution, I would be really really thankful 🙂.