[Build 42] Dedicated Server stuck on "Getting Server info" - [S_API FAIL]

I'm trying to host a Project Zomboid Build 42 (Unstable) dedicated server on a Digital Ocean Droplet (Ubuntu), but I'm stuck on an infinite "Getting Server info" screen when trying to connect.

The Error: My logs show: [S_API FAIL] Tried to access Steam interface SteamNetworkingUtils004 before SteamAPI_Init succeeded.

What I've tried:

• Firewall: All ports are open on Digital Ocean's firewall (TCP/UDP) and ufw is disabled.
• Network: Tested with and without Steam Relay. Changed Steam regions.
• Validation: Forced app_update 380870 -beta unstable validate multiple times.
• No Steam: If I run the server and client with -nosteam, it works perfectly and I can connect via IP.
• Files: Deleted ~/Zomboid files and reinstalled from scratch.