I have my server which kicks the player with these messages Reason":"Kicked: EAC: Heartbeat timed out"}

Have the player launch Rust via the Steam App, so it loads up properly first, instead of Nvidia or Rust Shortcut.  That should do it.  Otherwise, it's the ole Verify Game Files in Steam, clicking on RUST/Properties/Installed Files/Verify Files

https://help.steampowered.com/en/faqs/view/0C48-FCBD-DA71-93EB

TheBear

Have the player launch Rust via the Steam App, so it loads up properly first, instead of Nvidia or Rust Shortcut.  That should do it.  Otherwise, it's the ole Verify Game Files in Steam, clicking on RUST/Properties/Installed Files/Verify Files

https://help.steampowered.com/en/faqs/view/0C48-FCBD-DA71-93EB

is the server that kicks everyone for this reason