Something strange is happening with the online game.

Hello, Heroes fans! I apologize in advance if this is not the right place to post. The problem is this: I have friends, and we can all play together online without any issues using Evolve, except for one person. They can see the game, but they can't connect. Windows has been reinstalled, and we can play other games together without any problems. We can ping each other, and we have the same version of Heroes, but it still doesn't work. We've tried everything, and we're at our wits' end. We don't know what the cause is!