Well guess what.
My modem died as well, tech guys just left about an hour ago, everything works awesome with the new Modem.
It's directly plugged into my PC right now.
Also it seems to have a higher capacity or something because my download speeds have doubled.
Yeah it's still only 20 megabit buuut the old modem could only support up to 10 or something, it is very old from 2008-9 or so.
I had no fucking idea why they didn't raise my speed at all the last few years, turns out it happened like twice or so but I never noticed because of that, ayy lmao
So both the router AND the modem fucked up in the end, my devices are fine =)