Cannot connect to a specific game

I used to play this game with a friend, but, suddenly, I can't connect to his games.
Whenever he creates a new world, he goes in perfectly (He has a beefy computer and a good internet connection, so he always creates the worlds) but I can't connect to them, it gets stuck in ''Connecting'' and I can't do anything about it.
I can connect to other people games and play correctly and so he cans as well. He also gets into my games, but my computer isn't good enough to have a good server connection.
I've contacted Klei support via email before, but they told me to proceed here, I would be grateful if I get some help, thank you!