(This just happened, so I know I added my Apple TV as an extra hub. I'm trying to understand why.) So I used my HomePod as the only hub in my house. My notifications are set to record and notify only when it's a person. I just added a new Homepod Mini stereo setup and added the Apple TV 4K to which they are associated as an additional hub. I then moved the big HomePod to another floor of the house and left it as a hub. As soon as I added Apple TV as a second hub, I started receiving motion notifications from the 3 outside cameras. Previously, I only received notifications when a person was registered. Now, every move sends a notification, even if I haven't changed anything except adding Apple TV as an additional hub. So what did the addition of a second hub do to get all the motion notifications started? Can I easily go back to using the big HomePod as a single hub to see if notifications return to the way they're set up in the Home app, but shouldn't you add a second hub to leave all settings as they are? Before: HomePod set only as hub Notifications for cameras sent only when a person has registered What's happening: Now notifications appear every time the cameras catch any movement.