So, purchased this unit with 2 temperature and humidity sensors but they are very different. One shows temp 68.7, Humidity 15% and Dew Point 19 while the other shows Temp 68.3, Humidity 51% and there is no Dew Point display. Both sensors are sitting about a foot apart on my mantle for now while I was testing everything. The chart for the one displaying 15% humidity is a flat line which makes me think its not reporting, the other has a nice chart with lots of up and down activity. Did I get a bad sensor?