When I first tried playing multiplayer I got a few errors that were along the lines of "Disconnected due to inactivity" or "Connection timed-out".
The PC I use is an MSI Raider running Windows 11.
The Hytale support website is what helped me.
At first none of the options they offered were available to me until updated my WIFI driver.
I have a Intel WIFI "Killer" chip, so I went to the Intel drivers site and downloaded their tool. It said I needed to use the "professional suite" WIFI driver. I had to uninstall 2 WIFI driver programs in order to install the professional suite.
Once I did that I was able to follow Hytale's solution 2.
Although mine was an abbreviation of the name instead of the full name. So instead of "Recv. Segment Coalescing" it was "RSC".
And now I can play multiplayer!
I hope this helps. 😁