Am I right to say, when the above occurs, the drone is tricked to believe there is a "ground" at less than a foot beneath it?

Hi, It happened to me as well. I was flying in the city at the waterfront and for some strange reason, my Mavic air started auto landing without getting me any control again. The drone was only 15 meters away from me and it went straight landing into the lake and drowned. This is a serious issue and must be addressed. I have reported the issue to DJI I hope they will do something about this.