Google Nest Community

May have devices saved twice. Have you changed your wifi password lately?

Try Using IFTTT app. Set it Up for : If (set scene) is Activated, then (play Audio) on (Said Group). The IFTTT (If This Then That) App has helped me in a few similar situations in the past. Hope this helps.

Yes you can. Don’t allow him to pair said devices. 

Im in Central Cali BTW