3.8mm Safety Height problem


I have a Safety Height problem with my CNC EleksMill machine (https://www.banggood.com/ru/500mW-Desktop-DIY-CNC-Micro-Laser-Engraving-Machine-Assembling-Kits-p-1055378.html?rmmds=search).

Original Safety Height (3.8mm) helps to prevent your material from the damage and lifts Z axis up before it starts engraving. In my case Z axis goes down and damaged my material.

However, G-code sender shows work position correctly (https://www.youtube.com/watch?v=toxG8fZt-WQ).

I believe that the Z axis works upside down.

Could you please help me with it?

Thanks Phil!

I did check it. Works fine.

Also test continuity for each of the 4 motor wires on the Z-axis, if one of the wires are broken the motor will move the steps but direction will be at random.