So I'm filming for a class at a local community college tonight, and decide to try the new waypoint feature. I tried and tested it last night just to verify I had it set up right. Anyway, I get to the class early, pull the drone out to set up the waypoints and created 2 waypoint lists. The class starts, I start the drone and initiate one of the waypoint favorites. It does fine. I put it on the second one. It also does fine. I put it back into P mode and do some manual aerial shots. After that, I bring the phantom back to the starting point, put it into F mode and choose one of the 2 favorites. It uploads the waypoints, and begins. However, as it is going along, it starts 'sinking'... and I mean within inches of the ground. I put it back into P mode and elevate, but decide not to try that again until I can figure out what happened. Anyone else had this happen or know what might have caused it ?