Hello, whenever I try to connect to my friends I get stuck in "Connecting to game" then "Timeout in X seconds" then "Game server connection failed".

Two of my friends are able to connect to each other, but when I host, I only enter the game alone and they both get the connection failed error.

I tried verifying the game integrity, I tried reinstalling the game completely, I disabled windows firewall, I never had any connection problems with other steam or non steam games.

Any ideas ?