The heat is probably the problem. Our beans are doing much the same here in Oklahoma. They grew well, with our wet spring and early summer. But the blast of heat we've experienced, just a bit earlier than normal, seems to have caused them both to abort small beans and not to set new ones. I've been watering a bit and hoping they'll make up for it when the temps moderate.

George
Tahlequah, OK

Same here, and I also have the pole Kentucky wonders. They were super productive in June, when it was cool, but now they have slowed down. I think they are just taking a heat break and will resume in the fall, at least this is what happened last year.

The limas and cow peas are a lot more heat resistant. More like heat loving actually, they were moping around in June and now they are really growing (and flowering).