Do the leaves feel dry, or soft/limp?
I currently have two similar problems that I can't explain:
One tree, a satsuma, has many upward-cupped leaves that feel very dry, like it needs water. However it is well watered and also has many normal looking and feeling leaves. It has had these dry cupped leaves all year and they are still dark green.
Another tree, a limqeuat that nearly died, had normal looking new growth that I then noticed sagging. The leaves were dropping downward and felt limp. I noticed it had a scale infestation. I treated the scale a week or two ago but it still looks the same.
Your situation sounds sort of different from either of these but I'd check for bugs under the leaves that are bending down.