The game server seems to have a lot of memory leaks and unpredictable behavior when it comes to trying to terminate it in a controlled, graceful manner. Maybe the only viable way to host a server is to manage installing the updates and restarts via rebooting the OS and letting systemd do them. I.e., when no players on the server and update is available, reboot the OS and let systemd install updates and start the game.
The game server seems to have a lot of memory leaks and unpredictable behavior when it comes to trying to terminate it in a controlled, graceful manner. Maybe the only viable way to host a server is to manage installing the updates and restarts via rebooting the OS and letting systemd do them. I.e., when no players on the server and update is available, reboot the OS and let systemd install updates and start the game.