I have a phantom 3 standard. I lose my GPS signal is soon as the aircraft leaves the ground. I watched every video I could find. I have calibrated the IMU, compass and updated the firmware. In my area I receive 11 satellites. I have flown the aircraft about 10 or 15 times and it flies great but the GPS will not stay locked. I have not tried DJI tech-support yet I thought I might have better luck here. Anyone ever had this problem