I have the same problem with my green and gold blend beans. I got two good pickings and now they are dying. I called around to some gardening centers and they said the usual; could be cut worms, aphids, chemistry, dry soil, etc. I tried fertilizer and it helped a little, but I am sure it isn't the soil. Everything else in my garden is
growing like gangbusters. I have been watering every day for the last 10 days and I have a few new blooms but most of my plants died. I just replanted and I think there is plenty of time for more beans, especially this year. I heard it is expected to stay warm until october. I wish I had a better answer, but I am just as confused as you are. I live near Cleveland so pretty much the same climate.