UdpMessageMulticastSocket - Multiplayer doesn't work

I’ve been trying to find sessions using any online subsystem in Unreal Engine, but I can’t find any. I can host a game, but I can’t find my game. My code works 100% guaranteed, since I’ve used it in all my other projects. But all of a sudden it won’t look for sessions anymore. This is the error I get every second, even when I’m just in the editor:

I found a way to suppress the errors by disabling “enable transport” in the network section UDP in the project settings, but that doesn’t fix the issue of not finding any sessions. I’ve done a lot of research on this, and maybe 2 people have had this issue, but it hasn’t been resolved. So I figured I could give this a shot. I’ve noticed that this isn’t a project related issue. I’m having this error in all my projects all of a sudden.

Is this an engine related issue? Or did I mess something up. How would I fix this?

Thanks in advance!