It does update, but there's a delay, followed by an adjustment. For instance, when I open the app in the AM I would see say 45° as cabin temp, when I turn on climate - after a few secs I see it drop to 37° and defrost mode engage.
Maybe I didn't wait long enough? In the morning, I usually open the app to see if the car charged overnight (I have scheduled charging), and when I look at the temp, it would be like 75 or even higher. My garage in the morning is around 50; it has very little insulation. Maybe the cabin climate control runs while the car is charging overnight?