Agggrrrr so much hate for these devices. I bought a Mini for my oldest kid and now, when I pick up my phone in my downstairs office, hold it near my mouth, and say "hey Siri set an alarm at 7am", the phone briefly shows the Siri vortex and then stops. And I find out at 7am when my sad and confused daughter is startled out of bed that her stupid HomePod upstairs on the opposite side the house picked up what must've be…
When I want to talk to my phone or my watch I don’t say “Hey Siri” anymore, I just hold down the lock button (aka use it the old way). That activates Siri on the device without triggering any other devices. Since I generally have my watch or phone at hand, this has solved the issue for me. Still I wish the detection for “which device am I talking to” was better.