Does apple TV have to be "on" to use Siri for home automation?

the way it's suppose to work is an homepod, or appletv or ipad act as a bridge so ones iphone can control all the applekit stuff by internet because it goes passed the device at home which act on behalf of the iphone

this works fine for me with appletv or ipad acting as homekid boss

it require the appletv to have ac power connected or the ipad to have a battery

and the carrier allow data on the required ports https://support.apple.com/en-us/HT202944

Recent AppleTVs have a Siri button on the remote. I just tried it to turn on Homekit lights and it worked. First I woke the Sleeping ATV with the remote, then pressed the Siri button and just said "Turn shelf light on". It did not need the TV/hifi on for this to work.

This is a useful finding because I don't need to say "Hey Siri" first (which my Homepod would respond to and interrupt music playing)

You can certainly control Homekit devices from anywhere using an iPhone that is logged in with the same AppleID as the one used to set up the Home Hub. Usually the iPhone is either on the same wifi network or connected via the mobile phone network (i.e. 3G/4G). In some cases it might not work if your iPhone is connected to a different wifi network (which takes priority over the 3G/4G) and that wifi does not allow the necessary ports for communicating with Homekit. This sometimes happens with office wifis that are set for extra security. It seems to me that your problem might be a wifi issue but there is a possibility that the AppleTV is defective.

Hello,

As long as Apple TV is plugged into power it is in a lower power sleep mode which will still allow for HomeKit automations.