Update: Curiouser and curiouser... When I give the Siri command on my iPhone, "Turn on the TV in xxx", it works perfectly. But not so if I punch the button in the Home app on my iPhone. And the button on my Apple Watch has a red note, "No Response"; I get a similar response if I give a Siri command on my Apple Watch. And, in trying all this out, I suddenly would get an access code displayed on the TV in question, to be entered on my other Apple TV, which is serving as HomeKit hub (which got me trotting upstairs and downstairs a few dozen times - who says these devices are making us lazy? ;-) Anybody have a clue of what's going on??