Do you use any sort of VPN/something you connect to before steam and the server? If so, try disabling it. Always try a restart before giving up. Try reinstalling your internet driver (Uninstall, restart, reinstall, restart) just to make sure nothing goes wrong.

Do you use any sort of VPN/something you connect to before steam and the server? If so, try disabling it. Always try a restart before giving up. Try reinstalling your internet driver (Uninstall, restart, reinstall, restart) just to make sure nothing goes wrong.