[Mix Release] remote, stop, restart command are not working

I used mix release for deployment. After building a new version with mix release , I started the system as a daemon with IEx attached (daemon_iex ). I then checked the process ID of the running system using the pid command and ps aux | grep beam . It returned the same process ID. However, I cannot stop the running system using a remote command (stop ), either remote or restart . Each time a new version is built, I have to kill the process using the sudo kill -9 [pid] command and rerun the daemon_iex command. Can you explain what is happening with my system?