A few of my friends and I recently tried playing Grim Dawn together and are running into issues with severe lag. I have a fiber internet connection (gigabit up and down) and no issues with other online games, so it made sense for me to host, so I did. My friends experience severe lag when connecting to my game, and I experience severe lag when connecting to theirs. They also don’t really have issues with other online games AFAIK.
I did see that there are some troubleshooting tips for things like uPnP, Port Forwarding, and potentially some Static IP stuff but that stuff all kind of sounds to me like it is designed to solve problems with not being able to connect to / host a multiplayer game of Grim Dawn at all, which is not really the problem I’m having. Perhaps I’m wrong and one or more of those steps would address the lag issue as well? When I run the network test I see that UPnP is available but that my public ip visible to the internet differs from my router, but that seems like a fairly typical setup to me TBH. I’m not about to disable my windows firewall for anything so I’m really hoping that’s not the expected solution here.