When I host a game in zombies my friend can't join me but I used to host it on my old pc fine on the same router

[Named-ilyas]

When I host a game in zombies my friend can't join me but I used to host it on my old pc fine, also I don't find custom games to host one, and both my old pc and new have upnp enabled

[coder x64]

You should do port forwarding read this guide for more info: https://plutonium.pw/docs/custom-games/