Xbox One still running after shut down

Either Instant-On is set (Think PS4 rest mode) , or your console was finishing a download. The only other thing I can think of is it might just be cooling itself before shutting off. I don't know if it can sense the temperature of the console or not.

Your xbox may be set to continue receiving updates even "off" to resolve this set to power save mode.

https://support.xbox.com/en-US/xbox-one/console/learn-about-power-modes

If you did a Full shutdown from Settings>Power the console will close any open games and apps running as well as finish any downloads or uploads (clips, screenshots) to XBLive before powering down.

Hi n30np1xel,

Thanks for your post. I understand you are experiencing an issue with your Xbox One still running after being turned off. It sounds like your console is set to the instant-on power mode. This power mode is available to allow your console to install updates
when powered off, return you to the dashboard quickly after startup, and allow you to remotely install games to your console from your Xbox App on PC and Mobile.

You can turn this setting off by following the steps here:
Xbox One - Power Modes and setting your console's power mode to "energy-saving".

Please let us know how this goes.

For me its normal ! Usually when that happens its Auto updating an App or Video Game on its own while Shutdown which can be fixed in Settings for Updates/Downloads otherwise it does take a second sometimes for power off delay usually 4-5 seconds !