Hi Steve, if you haven't found any insect and the leaves were like this before spraying, it may be the reaction to the fertilizer as well. And how do you fertilize it? Do you water it first,wait for a while and then fertilize?
To be honest,I'm not sure if it's the virus or the fungus or maybe just a reaction to overwater and fertilizer. But I would check the roots, maybe repot, and minimize the watering. Plumeria can be without water for a longer period.
No worries about the tiny white spots. I used to have them on some of mine as well and the plants were doing just well... Blooming too.
BTW ... winter is dormant period, it's good for Plumerias to rest for a few monts. That means they're without leaves, watered occasionally (once a month or so), not fertilized, and in the room with temperature around 15 degrees.
