Lego Minifigure Face Paint Issue

[LegoSims20]

So I purchased a full box of Lego Harry Potter miniatures yesterday, sorted them out and got myself a full collection. Today I was looking at them all and noticed Hermione had a black smear on her face and I tried wiping it with my thumb and her entire face smeared, and now looks extremely faded. I was worried that I’d maybe felt her packet too hard, but I’ve done this with many Lego figures in the past (as I’m sure many do) and no other HP figures had this issue. And I don’t think I could actuallly rub a face off. Now I’m wondering if it was a faulty paint job. It just seems strange and makes me a bit worried for my other figures. Has anyone else had any issues like this, or are able to provide a possible explanation? Any answers are appreciated.