I have only had these 2 Nest thermostats for about 2 weeks and it seems last night my temperature went down to 66 degrees F instead of the usual 68. Now this morning I find that the rooms are at 63 degrees which tells me the thermostats are not asking for heat to be transferred to the rooms. I took one of the devises off of the wall and put it in front of my fireplace to see if it would register a temperature increase and it showed 75 degrees F so the sensor is working. I checked if they are on a hold and I do not see any signs that they are on a temperature hold. What other troubleshooting should I try?