Did you apply any fertilizer, ever, at any time? Did you try magnesium at all? Try a tablespoon of epsom salts watered into the root area

Yes, I have fertilized once so far this year. No I have not tried magnesium as that was just a guess of mine base on some photos I saw online that looked similar.

In past years I have fertilized more over the course of the season and the beans have looked the same. Perhaps this fact may or may not rule out under fertilization.

Would application of magnesium via epsom salts show improvement in the problem leaves or cessation of additional leaves exhibiting the problem?

Thanks

Would application of magnesium via epsom salts show improvement in the problem leaves or cessation of additional leaves exhibiting the problem?

If this is an ongoing problem, maybe you should have a soil test done. Not enough info in your posts for anyone to be able to tell you exactly what is wrong. You could be deficient in some mineral or have wrong ph or a disease or virus, you could be getting herbicide overspray, or salt from a road or driveway, maybe it's too hot and dry, maybe you have contaminated mulch applied, maybe you plant in the same place every year and a virus or disease has established itself there, maybe your vines are competing with tree roots, maybe you are planting varieties not suited to your climate, maybe you need innoculant. It could be a number of things.

I try different things and see what works. If you think magnesium might help, try it. How could it hurt? Let us know what happens.

Do you still get good beans every year? If you just want good beans to eat every year, I would not worry about leaf appearance. Lower leaves do die off as the plant grows, this is normal.

Your right the list of things that could be the problem is very long indeed. I was only hoping that someone with more knowledge would be able to identify what I am experiencing by visual inspection.

"How could it hurt?"

As I see it if there is a multitude of things that might be the problem then doing something that, for me at least, has unknown consequences could potentially exacerbate the problem, cause others or mask what is happening. Therefore just trying things without knowing they potential effects may not be the best course of action. I will admit that without any possible solutions I am likely to try different things and see what works come what may. Still I hope someone may happen upon my photos and be able to identify the likely problem or causes.

Yes I have gotten good beans, however, the leaves appearance doesn't look right and is a bit disconcerting even realizing that, yes, lower leaves do die off.