SOLVED: Can't connect to server

[en33-08]

I think I found the solution and think know what the issue was.

My PC was on 2.4 GHz connection and my tablet on 5 GHz. When I disabled the 5 GHz connection, it started working because my tablet now connected to the router via 2.4 GHz connection.

The issue is that I can't force my Samsung tablet to be on 2.4 GHz connection only because Samsung being Samsung, I guess. And on my FritzBox I can't force single devices to use either 2.4 GHz or 5 GHz. I'd like to use ethernet or 5 GHz but there's unfornutely there's a concrete floor seperating me from the router.