Q.Why Wont My Pole Butterbeans Make Beans?
They make a lot of vines and blooms, but only a handful of beans on a 60 ft row. I have them growing on a nylon fence 6 ft high.

Certified GKH Gardening Expert
This is a pollination problem. Without pollination, the blossoms will not turn into beans. These articles can help you improve your pollination:
https://www.gardeningknowhow.com/garden-how-to/beneficial/insect-pollination-process.htm
https://www.gardeningknowhow.com/garden-how-to/beneficial/creating-a-pollinator-garden.htm

My father (age 93) has always grown pole butterbeans. He taught me (and insisted) that I never use fertilizer on pole beans. I don't and they bloom and produce beautifully. He said that if you fertilize you will get vine and not beans. Try it and let me know.
Also, sometimes the bees are not very active and that can effect your crop.