I've noticed something weird lately about the Homekit connection.
I use Google Mini's for TTS. When the Google announces something, my Homepod mini either tries to control something or says the item doesn't exist. For example:
I have motion detectors outside that thru HE will announce visitors. The other day Google said "Visitor detected at front Garage". Immediatly Siri tried to open the garage door. It didn't suceed as I had some interlocks in place. I have since changed the name to something other than garage door.
Today Google said "Visitor detected at Front Door". Siri responded "Front Door Is Closed".
So my point is, why is Siri doing something without hearing the 'Hey Siri'? By the way the motion switches or the triggers to Google are not assigned to Homekit Integration.