I've tried turning soft limits off and still the same issue. I've also tried with and without homing the machine.
I've now renamed the mach3 folder, and done a fresh install, copied over my XML file and get same problem.
Really got me confused this one. If I try to configure the plugin for the controller, I can make the motor spin in both directions buy selecting the option circled in red. But I can't jog the axis using the arrows on the same screen.
Surely this means the hardware is all ok still, but it's a software issue?
Edit - I know the screen shows the Y Axis, but I was tesing the Z axis, just went back for a screen shot