Plutonium

I tested this moments ago and it appears that g_password works correctly on the dedicated server for both SP/MP.
I suggest the OP to verify that they set the password correctly. Or lay out exactly what they did and what went wrong.

https://plutonium.pw/docs/improved-security/

T4 isn't the most stable
Maybe try to load the mod manually yourself (the one from the server) before joining the server