Walking a lot, especially on hard surfaces like the mall or food store, or even lots of back and forth on the ceramic floor in the kitchen will leave me with severe leg pain by nighttime. For me it is my legs and knees more than my feet. The stiffness will also be a lot worse on those days.
I have found that walking on softer ground is a lot easier on my legs.
I am not suggesting that something else isn't going on, but don't underestimate the pain that PN can cause all by itself. It is one of the more painful and difficult to treat conditions.