After the process is terminated, it's taking some time to return exit_code and our frontend code is waiting for exit_code to notify the user that the process is terminated by the user. Also Stop Process button is not getting disabled and which is misleading the user that nothing is happening, which may result in user clicking on the button multiple times(Backend is throwing process not found exception due to this).
To fix this, I have disabled Stop Process button after the user clicks on it and added a message "Terminating the process..." till exit_code is received.