Plutonium

So I have 3 friends I am trying to play with in a private lobby match. 2 are using the same internet and I am sharing the same internet with the third person. I cannot join my friend that I am sharing the same WiFi with but I can join one of the other 2 friends fine. However they can not be in the same lobby as well but can join me fine but only one of them can. It will kick the other person soon after the other one joins. And I’m not sure if this other Issue plays into this but none of us are able to join a regular server through online play. Any help would be great