A loose prop could of been your issue as others have mentioned. Active "braking" can do this to a loose prop. I have been flying quads for years so when DJI brought out "active braking" I didn't really like it. I adjust the settings on the braking as low as it will go.
DJI does not recommend using the wrench to tighten the props. You should only use the wrench if they are stuck on. Over tightening the props will also damage the hub. I use my hands and tighten them "just enough". I know, how much is "just enough", well, I go by feel so it is hard to describe. It is as tight as I can hand tighten them.
