Getsockopt Error

I have a modded multiplayer server with some friends on lagless.gg, but one of my friends keeps getting the "getsockopt" error. We've tried the fixes with:

- DNS
- IF4V
- Restarting network
- Restarting computer

But no luck. Any advice? This friend is in the UK, the server is localized in NYC. Should I have moved it to Europe for a better connection for my friend?

Thanks!