All the above suggestions apply plus:

Experiment with different foot rest postions since the angle of your legs can make a difference. Remember there placement if you ever need to readjust them after lending out your yak.

If you have tight hip pads, check out if they cause any undue pressure. I once had NBS on one leg only and found it was caused by my pump which I had placed between the hip pad and hull. I could barely feel the pressure but it was there. Once I changed the pumps position it went away.

I changed and remade my seat 3 times before I had no more NBS. But I have no padding of my own (read bones only) and rely on the seat instead. Can't paddle for long in any other kayak. The best way to solve the problem is to put your kayak in the lounge and read a book. When pins and needles start, change something on the seat or leg position and try again until its sussed. Just don't let your mates catch you out (: