I just bought the digi q dx and did my first cook, a boston butt. I set the temp at 225 and it held at that temp for the entire cook. I noticed my dome thermometer read about 185, is this usual that the dome temp is 40 lower than than the grill temp. if so, i must have been cooking a lot hotter in the past than i thought. Or should i trust the temp for the dome and not trust the temp on the digi q?