No, no difference... lowered Vref to 0.15V . But maybe there is something wrong with board? Btw I am using this one of these type of boards
www.amazon.com/Stepper-Motor-Driver-Cont...graver/dp/B074FT52T3
. Plus when I connect focuser on Ekos, on Arduino Nano Rx and TX leds starts blinking. Maybe that would help ..