It looks like the grind adjustment screw on top has come a bit loose, and you should adjust it a little and re-secure it, so that it gives your favored grind size, but stays in place.
I'm not sure how your grinder secures the adjustment screw in place.
Yeah, thank for the thought. The screw on top was tightened before shooting the video, but you did reminded me of the other screw on the button. I don't have high hopes though.