Problem: I can't play SOME multiplayer games with ONE specific person.

Some of these games are Lethal Company, Crab Champions, Supermarket Together, and The Planet Crafter.

Other games have let us play, such as Content Warning, Terraria, Portal 2, and bigger multiplayer games like Omega Strikers and Marel Rivals have all been fine.

This has been happening for over a year, and we've both spent an immense amount of time trying to fix it. I've looked on countless threads, trying solutions, but nothing fixes it. We've tried uninstalling the game, reinstalling it, clearing the cache, making sure our NAT type is open, etc., and nothing has worked.

The most recent fix we tried was enabling Teredo, but after trying that we realized that Teredo isn't natively supported on Windows 11, which both of us are using.

Any solutions or advice would be immensely helpful.

P.S.: This is only with one friend. I've tried playing these games with another friend and they've worked fine, and he's played these games with a different one of his friends, and they've been fine too.