Phew Man
Phew, I have been very fortunate then.
1. Sonos Beam sound bar configured for Alexa, and HDMI CEC to Smart TV
2. Alexa talks to my Nest devices.
3. Nest devices configured not to auto software update
4. All works fine
"Alexa tell nesty to stop being naughty"
Oh no, I have just mentioned something cloudy works. Cue the great flood and wild fires hitting my suburban vicinity!