It could be the heat. Last year, when we had heat waves in June and the first half of July, mine seemed happy at first But then they just shut down.
The tomatoes came back quickly, but the peppas didn't start setting fruit till much later than usual, and never did produce as well as they usually do.
maybe they need some ph balance in your soil our alkaline soil here plus the cool nights makes for some very nasty peppers...even my jalapeños scare the hell out of people
cool nights makes for less peppers but in our case less is more....heat wise my carribean reds are so nasty hot I can recycle them in oil for my hotoil over and over