We have three users (phones) in our house, trying to control, for now, only two Meross switches. (I want to add more). In the Home app, in my Garage room I have an accessory called Light. If I say “Hey Siri, stop Garage Light” it works. So is my wife’s phone. But if my daughter says the same thing on her phone, she’ll get an answer that Siri doesn’t see anything with that name. The Light accessory appears in the Garage room in the Home application, just like on my phone and my wife’s. But things are getting really misleading. I have another switch in my Sauna room called “LED lights”. If I say, “Hey Siri, turn on my LED sauna lights,” it works. So is my wife’s phone. And the same with my daughter’s phone! So, somehow Siri doesn’t interact with HomeKit on my daughter’s phone. Yes. It just doesn’t work for the garage light, but it does work for the sauna lights. At a loss for what might happen.