Sorry to hear about your experience with your Nest thermostat devices. I want to dig deeper into them.
A few questions — what type of Nest thermostat do you have and when did you first experience this concern? What type of system do you have? Also, when was the last maintenance check for your HVAC system? Aside from clearing the schedules, please provide a rundown of all the steps you've tried so we can pick up from there.