Welcome, Lamissy!
That describes what a lot of them were doing in Phoenix, AZ this past summer. With us, it seemed to be pure heat damage. It is just now getting cool enough for them to relax, but few are still left alive.

If you garden in southeastern CA, you may be having the same difficulty. Delonix1 also tells me that there is similar heat going on now in San Diego, so if you are in that area, the same thing may be happening there. Other than that, I would check the drainage, since root rot shows similar symptoms. More rarely, lack of magnesium may show up that way, too, so you might want to double-check your fertilizing. I admit fhat I would need more info for a less scattershot diagnosis.