This means that youre g-code is commanding an rpm lower than the minimum pwm % that you have set.I either get "PWM bumped error"
If you want help, you need to be more specific about what the problem is.
Try the ones you actually used. You assign one pin to the spindle step pin, and one for your M3 relay. You should know which pins you are using.I have tried every port / pin configuration I can think of.
Try explaining exactly what is happening, one step at a time.