When I try to either join a match or host a match with a friend, we can't connect to each other. We can join the room, and one of us clicks "Ready", but it just says "Waiting for host...".

If my friend attempts to join a game I host, it says "Failed to join room" for him.

We can still chat to each other and see each other in the player list.

We have both tried using windowed mode, but still nothing.

Are there ports to forward or anything like that?