Webdeck,
I posted this problem a few days ago in the Homekit Bridge forum, but I just realized it probably belongs here.
After upgrading to iOS 12 (although probably not an iOS 12 issue), Siri now will not send an on or off command to a device if she thinks the device is already in that state. This affects all of my X10 light switches after I turn them off manually as well as manually controlled locks, rolling shades, etc. I don't see any attempt to control them in the Indigo log or anywhere else except that Siri responds as if she controlled the device. I don't think there is any Siri or Homekit log available so I don't know how to check further.
It also just occurred to me that it's possible, but unlikely, that the commands are being filtered by Homebridge; ie, does Homebridge look at the device state and inhibit a request if the device is already in that state? Is there any Homebridge or Homekit log available that might shed light on this?
I've made a forceful case to Apple that Siri is causing this new behavior and I hope I won't end up with egg on my face.
Thanks.
--Dave