There is a small thing on the left of the heatsink that looks like a silver circle on top of a square, it's actually a small potentiometer used to set the current output of the driver.
You can use a small philips or flat blade screw driver to adjust them, clockwise is more current anticlockwise less.
Too much current and the drivers will repeatedly go into protection mode and the steppers with chatter when enabled.
Too little and there isn't enough torque to move the axis.
They do not come set to any sensible value.
They can be very picky about the setting depending on the steppers.