Hello, this is due to the way Windows is set up, if you leave a game or movie running, it will keep your system running because it believes that you wish to keep using it, such as to watch a movie without needing to move your mouse every 5 minutes. If you wish to override these settings, it should be possible through the Windows Settings, or through the use of a third party app or you c*so create a shortcut. If you are unsure on as to how to do so, Google is well versed in all versions of Windows.

Sadly, I am not able to, I personally use a program to put my computer to sleep.