For everyone getting this error:
I followed the usual advice of adding antivirus exlcusions and disabling IPv6 (Which can be found at the end of this post)
BUT ALSO: Make sure you run Kyber Launcher as an Administrator. That's what actually fixed it for me
Disabling IPv6: https://www.windowscentral.com/software-apps/windows-11/how-to-disable-tcpipv6-ipv6-on-windows-11
Antivirus exclusions: