Are you dry or wet right now? Some areas of TX are having lots of rain, some aren't. If you're in a dry area, you could be looking at spider mite activity or heat stress. Both will cause leaf-drop. Water is the answer to both. Water wand, set to 'jet', spraying bottoms of leaves will dislodge the spider mites. Do this 3x a week until problem is no longer evident.

For dry conditions, increase your irrigation time and spray the bush with water every morning to increase humidity.

There could be other problems but these would be the two I'd check first.