Dwarf Bean Problem

[cazp]

Hi All, it's been a long time since I posted here, as I don't grow as much veg as I used to, due to available space.

This year I decided to do a couple of pots of dwarf beans but they appear to have an issue as pictured below...the adjacent plant which is a different variety seems fine.

They are in a quadgrow, so not lacking in water. Any advice appreciated, many thanks