To disable your server to appear from the Game Servers List, apply the following steps:
1- Login to the game panel
2- Navigate to your server and click on "Commandline Manager"
3- Select "Non-Public Listed [Optimized]"
4- Start the server
Notes:
Non-Public Listed [Optimized] = Server will be disabled to show in the game servers list
Public Listed [Optimized] = Server will be enabled and it show in the game servers list