[HL25] Listen Server Steam Network Issue [SteamNetworkingSockets] Error Code 5005

[ｃｒｙｐｔｉｘ]

I'm experiencing issues very often when launching Half-Life 1 and attempting to create a listen server with Steam Networking enabled. The following error messages frequently appear, preventing server connection :

Could not establish connection to Steam servers.
[SteamNetworkingSockets] Cert request for invalid failed with reason code 5005. Failed to connect to Steam
[SteamNetworkingSockets] Cert request for invalid failed with reason code 5005.  We're not logged into Steam

It seems that the server attempts to use the IP address of my vEthernet (WSL (Hyper-V firewall)) instead of my regular Ethernet adapter, which might be contributing to the issue.

This problem makes it impossible for other players to connect to my server. The only workaround is to re-create the server, and changing the map using changelevel command will not fix it, you must Create server again from the main menu. On the second attempt of creating the server, it usually connects to the steam servers and acquires a FakeIP.