I'm using the SS plugin v015ogx2 and my BB is the DMB3621-4A and everything is working well.
If you can work with the LPT port, should work with the SS.
Maybe you can try with a lockdown plugin.
My driver for SS is v2.08.20
If you go to Plugin Control, SmoothStepper Data Monitoring. Are Sequence ID and Device Time data changing?
Do you have in Plugin Control, SmoothStepper ****************** Config, activated the output mode in Step and Direction?
My EStop is on pin 10 with active low activated