Quick Apple TV question

tvOS and Apple TV Apps

Hi all,

I’ve recently bought an Apple TV 3rd generation and loving it, but there’s one small thing which doesn’t seem to be working. On Apple‘s website and on other support articles, it says to put the device to sleep, you hold down the play/pause button for 5 seconds when in the main menu, but this doesn’t seem to work for me. Is there a setting for this anywhere?

Thanks for any help.