@Kristopher did you by chance roll a virtual switch that performs a mute/unmute command?
Your base device controls my receiver just fine, but Amazon Alexa/Echo does not detect the device. I’m assuming because it needs it to be an on/off type switch for Echo to see it.
My ultimate goal here is simply “Alexa, turn on mute” and “Alexa, turn off mute” voice controls.
If you haven’t rolled this yet, I’m happy to do so and send a pull request. I’m guessing it’s just a modification of your av-button-on and av-button-off code.