If you look on youtube, there are a couple of videos explaining what's going on. Basically when they made the teeth in the post, they did not cut them deep enough. And it also seems the square hole the post slides up and down is not formed very well.
So the catch has poor engagement in the teeth, and the post is a little wobbly. If the vehicle shifts while on the stand, the teeth can come out of the catch and it will drop.
That's the biggest problem with overseas products. They do not seem to have any quality checks and quality control. It just flies out the door regardless if it is made properly or not.
If you took a grinder and ground the teeth deeper, and then shimmed the hole tighter where the post runs up and down, I bet you could fix the jackstand problem.