I’ve been looking/playing with mine trying to figure something out, and while both my screws stay tight, I do notice that I can loosen one screw noticeably easier than the other, and that the tip on this on appears a bit fatter. I took a picture, but I’m not sure if it really shows well…
Maybe check yours and see if you can tell a difference? If so, maybe trying a different screw might fix it.
I also noted that the tips appear scuffed. I mentioned this in the other thread, I know that this has come up before, and some noted it goes away over time… maybe it gets a little scuffed up and secures better.
Anyway, if you do see a difference, you could get another screw sent out to try. You could also try swapping sides to see if the problem follows the screw, that would also tell. That’s about the only reason I can think of.