I agree that it looks like it was sprayed or misted before you got it. Notice how the newer leaves have no residue? I'd try washing the leaves with a soft cloth dipped in plain distilled water— a gentle rub won't hurt them. Then dry with another soft cloth. See what happens in a day or so. If it reappears, return to this thread for more problem solving. Whether it's from pests, disease or residue, wait until you know what you're treating before applying anything other than water.
