I went to fly today and notice the red arrow did not point towards my home point. nor did it point toward the H on the map. this is weird because it always pointed towards the red dot and if I point the arrow aka AC towards the red dot it would point towards the take off point. anyway I landed the ac and tried to do a compass calibration but it wouldn't let me , it was like to touch screen wasn't working. I kept touching the compass and it would not open up for the calibration.The touch screen worked on other stuff so any idea whats going on.