Home assist via atom echo randomly speaks

Hi
I followed this guide $13 voice assistant for Home Assistant - Home Assistant (home-assistant.io).
but the echo device quite often just says "Sorry I don’t know how to do that) even when it hasn’t been asked anything. Sometimes I hear it saying it when no one and no noise in the room. It set up to respond to the wake word ‘Hey Jarvis’
It does respond to hey Jarvis but usually takes repeated attempts form me to get it to do what I want it to do.
Does anyone know why it the assist randomly thinks its been asked something? What log file might give me an indication of whats happening to trigger it?