I've noticed that after I've been flying for 10 min or so, my altitude will not be accurate anymore. It always says that I'm much higher than I actually am. I flew for a little while today, and decided to bring it low to the ground (15' or so), but the app said I was still 100' ft high. Similar thing happened a few days ago, when I was no more than 50' high, but the app reported I was 130' high. I've already calibrated the IMU, which didn't help. Because of this issue, I can not get the VPS to enable when trying to land. I also experienced this same altitude issue on my P2V+. I'm just wondering how many other people have this issue. Thanks!