Solved Changing server header image?

You do not use + in the server.cfg, it's just one command per line. The + is only used if adding commands/settings via your .bat/.sh.

The server.cfg file is manually created by you under server/identity/cfg. If you only used the command via your console, then it will not persist between restarts. You need to add it via the server.cfg or your startup script.

 

Was it ever 550? It's been 512 as long as I can recall. It should change whenever you use it though, but for persistence you'd need to add it to your startup using one of the previously mentioned methods.