Start the Launcher - start Arma3 - use the editor / game - periodically Alt tab back to the desktop and start other applications then Alt tab back to Arma3 and the editor/game - after a while exit Arma3. Start task manager and check if Arma3 is still running. About 60% of the time Arma3 is still running in the background and failed to shut down correctly. This only happens when starting Arma3 with the Launcher.