Apple TV won’t turn off

To turn off your Apple TV using the remote, you can follow these steps:

1. Press and hold the TV button on your Siri remote.
2. A menu will appear on the screen with several options, including "Sleep", "Suspend", and "Restart".
3. Use the remote's touchpad to select "Sleep", which is indicated by the Zz icon.
4. Press the touchpad again to confirm that you want to put the Apple TV to sleep.

Your Apple TV should now turn off and go into sleep mode. If you want to turn it back on, you can press any button on the Siri remote or use the remote app on your iPhone or iPad.

holding in the off button for some seconds turn my appletv off

more info

How to turn off or restart your Apple TV – Apple Support (UK)