Runner bean plants dying off

[ameno]

I grow several varieties of bean, both runner and French, for dry beans. Previously, I have found that French beans tend to start to die off in late September if I'm leaving the pods on for drying, presumably because they are annuals and thus, having set plenty of seeds, have reached the end of their lives. Runner beans, on the other hand, keep growing until the first frost, even when laden with mature beans, presumably as they are perennials.
This year, I have grown a new variety of runner bean, "Black Doulting", a black-seeded variety. I have found that a lot of these plants are behaving like the French beans do, in that, having set a lot of seeds already, they are now dying off. Before anyone asks, they are definitely runner beans.
I suspect this is a varietal trait, so does anyone else have any experience of specific varieties of runner bean giving up and dying late in the season, where most would continue until a frost?

[Jungle Jane]

Try growing them again next year,it might’ve just been the weather this year,my runner beans usually have extra flowers that grow but they seemed to have given up early this year.