The magnetic knob on my new 30" Induction Cooktop does not work very well. It jumps around a lot and not very precise . I turn it and it nothing happens then more turns and it jumps up to 6 or 8 or 15. Turning down same thing. You'd think it would go from 1 to 2 2 to3 3 to 4 etc. But no. Am I doing something wrong?
