Curling leaves on azalea

I live in the San Francisco Bay Area, near the southern end of the bay. A few days ago, I discovered that the leaves on one of my Southern Indica azaleas (a variety called 'Southern Charm') had curled up along their length. Other than the curling, the plant looks perfectly healthy. The leaves aren't discolored and show no signs of distress or insects.

Here's a closeup of one cluster of curled leaves:

wider shot showing the foliage area of the plant (it's a standard/topiary form): the branches would not be visible; they'd be hidden behind the fully opened leaves, as with the low- growing azaleas in the next photo.)

And a photo of the full tree (note the happy bush-form Southern Indicas below it):

've been reading back postings on this group and the information on some websites, and the two most common causes of such curl seem to be cold, windy weather, and fungi. Although we did have some high winds several days ago, they were accompanied by rain and took place in 40-50-degree weather, so it seems unlikely that the plant is protecting itself from cold, dry conditions.

That leaves me wondering about a fungus. But wouldn't that cause more damage than just curling?

I put some ground-up oak leaves around the plant a couple of weeks ago, along with some coir mulch (Mulch Block). I kept the mulch a few inches away from the trunk of the azalea (it's a standard/topiary form), but I treated the oak leaves as a soil amendment and let them get quite close to the trunk. Was that a mistake? I did the same thing a few months ago with no problems, but maybe it wasn't a good idea in rainy weather? I've now pushed everything out several inches, although if it did allow a fungus to take hold, I realize that moving the leaves and mulch isn't enough to solve the problem.

As you saw if you looked at the wide-angle photo, I have other Southern Indicas in the same landscaping bed, and they're all looking great. They were put in two years ago; the Southern Charm went in last spring. So the others are better established, if that matters.

Should I put some fungicide on the roots, or could something else be causing the leaf curl?

Thanks! Patty