Hi, Najnielkp
This may be a leading low, leading high issue with your OPTO Isolator board.
Try setting In Config, Ports-Pins, Motor Outputs Changing your Dir, STEP LowActive setting to Opposite state, X to Check or Check to X.
Some controls are sensitive to leading and trailing Edge Pulse's.
Try this one First, It could also be In Config, Motor Tuning the Pulse Width set to low, Step, Dir Pulse's, If there set to 0 set them to 5,
If that fixes it, back them down till problem then backup 1 level. ( time that the Opto's have to see Mach Pulse's.
Hope this Helps, Chip