Help with a Passionflower disease?

Heya friends. I have a big Lavender Lady who isn't looking all that good. The surface of all the leaves look like they have hard water scale on them. You know that white residue you can see on glass or your car windshield from water? It looks just like that and I've seen water do that before but never to cover an entire plant. I can't describe it any better than that. I'll take a good picture later so I can show you all. The plant is still growing and blooming, it's just not thriving like I'm used to. She's in a large pot with great soil, she should be all kinds of happy.
I'm at a total loss for any explaination. This has been the worst season gardening wise for me since I've been gardening. First we had a few very late freezes that weakened many plants which made them prime candidates for infestations of all kinds. It has just been 1 thing right after another it seems and I can barely keep up. What a drag.
Thanks all, JD

JD, I was reading in this forum a day or so ago, and ran into this site. Maybe you've already stumbled upon it yourself, but if not, maybe this info will help you out.

Good Luck,
PiggyPoo :)https://www.ransomgardens.com/ransomgardens.nsf/pages/passifloradisease

I haven't seen this site yet. Thanks so much for looking it up for me;)
JD