Barnman wrote:So when I ask Alexa to turn on the den lights, instead of saying the device is not responding, it says “den doesn’t support that”
I can get that behaviour if I ask Alexa to "Close study curtains" for example - I have to say "turn on study curtains". You can get round this by using Alexa Routines. The only downside of this are a) it is something else to setup and b) you have to go through the process again if you have to forget the device (for any reason) in the Alexa Web App.
In your case, it would explain why nothing comes through to the plugin if Alexa doesn't think that Den Lights is supported (for some reason).
So Alexa doesn't appear to be recognising Den Lights as a Hue Lamp . What does the Alexa Web App show the device as; a light bulb?
The mystery deepens.