Hello, I have a couple of plumeria trees in the house and this winter they started developing these tan or whitish spots on the leaves. I've rubbed them with alcohol solution once but this didn't change anything and I can't tell what they are. I have had spider mites on them in the past but this doesn't look like them compared to previous infestations that I've treated the trees for. Any ideas what this is? One of the pictures shows the leaves emerging with black tips or edges on the leaves. I am assuming this is black tip fungus? Thank you.