So Lucky, look very closely at your bean plants. Have some reading glasses to help. Are you seeing any little iddy bitty cobwebs? They would be found at the leaf nodes. If you do see any micro webs, those are made by micro spiders called spider mites, the onliest type of spider that is herbivorous. Spider mites eat on plants as if the plants were animals, sucking on plant blood, that is, the liquid that plant makes and uses. That very effectively kills plants. Spider mites are hard to kill, the little plant vampires.
Another thing it could be is variety/location. Call it magic or something, but it is true especially with beans and other legumes, that some varieties have a hard time at some locations.
I have heard of expert professionals moving, then planting their Runner Beans, and having total crop failure. What that expert seed grower did was find a local heirloom variety of Runner Bean to grow.
Right here, at my place, I am having the heckevest of a darn time growing Rattlesnake Beans, both of my old selection and of High Mowing's selection. Also, some of my selections of White Greasy are roughing it.
I planted about 40 varieties of Beans this year, only over half my usual count, but some are brand new to me and others are new varieties I'm developing.
Some varieties are just plain slow to start flowering, others are quick. I have pole varieties that flower even before making runners. Some have not yet begun to flower. The really late to mature ones, well, that is exactly the reason they are so rare. They take up space all season. But then, some of those late ones have the coolest and best dry beans you'll never find in your Safeway. Flor De Mayo shellies in a grocery store? Greasy Cutshorts in WalMart?
I have heard tell that in some parts of Missouri they often have crop failures with regular vulgaris beans. Something about the kind of hot it gets there. Find some real old timers in your area, see what kind of beans they grow.
That's your task fertheday. Meet some oldtimer gardeners in your area.