I've had this Paph for about 4 months, and recently it's gotten some spots that I'm not sure whether I should be worried, or if it's natural, or how to take care of it. It's only happening on the older portion of the plant (the unaffected part is the one that has bloomed while I've had it, and just finished less than a month ago). I don't see any sign of pests, and none of my other plants seem to have any issues, so I'm at a bit of a loss. Here's a couple pictures: