You guys warned me to keep an eye out for burning on my paphs...Always had this situated a couple inches past the end of the grow light, but it was in a wine glass which brought it closer to the light. Maybe that extra height was too much?
My Paphs get spots like that as well, although I think mine are from water on the leaves or in the crown, then as the leaf grows out the spotted part gets pushed outward. I assume they are localized bacterial or fungal infections of some sort.