I decided to put on my prop guards for flying in my yard , lots of trees. Everything was fine. Only flew about 20' high just cruising up and down the street slow , was a little breezy. All of a sudden it started oscillating back and forth and jumping around. I switched to atti then back and got control but it still seemed shakey. I landed right away. I pulled off the guards ( quick disconnects) and flew in another spot in my yard. Yes I know about vrs , but I was hardly moving almost hovering, so I don't really know what it was. But I almost lost it. Prop guards did save me when I hit some leaves.