So I just got a phantom 2. My second phantom. I'm fairly experienced so I know this is not normal. I took my phantom 2 for a few test flights.. Everything seemed normal. Then yesterday I did the same and the phantom would not stay in the 10 m radius for hover. Then I started moving it and it just started decending and hit the ground. GPS mode was flipped up, I had a home lock... Green lights flashing. Battery was at 100%. both switches on the controls were flipped up. I did a compass calibration successfully. So I swapped out batteries for another at full charge. It went up 3-4 feet then without me telling it to, just came straight down. Not the controlled decent like the self landing when it does a down, stop, down, stop, but straight down and hit the ground. Stock props... H3 3d gimball and go pro. Nothing else on it. Tries a IMU re calibration successfully. Still happens. Please help Thx!