Hello @Octavian, thank you for getting in touch!
We’ve just checked the servers and they seem to have no sort of issue, did anything change on your friend’s end, such as ISP or Firewall? Has he tried to reset his router?
Does he have any mods installed? We’d recommend uninstalling all mods since they’re not allowed on official servers and there’s a chance that they could mess with his serverlist.
Also, this workaround we listed in the Technical problems thread seemed to help other players in a similar situation in the past:
1-) Run command prompt as administrator
2-) Run command “ipconfig /flushdns” (without quotes)
3-) Run command “netsh int ip reset” (without quotes)
4-) Restart your PC