I went from Texas to Alabama. I hooked up my Shield, controller, and P3A. I tried to do a compass calibration several times but never would take. Exasperated, (since I bought the Shield for the P3A) I hooked up my Galaxy S6 phone, successfully calibrated the compass, and flew my mission. Why would the compass calibration not work with the Shield? I have flown with the Shield several times at home in Texas.