Hello all. I encounter with the following problem: LW3 in CNC mode,

Hello all.
I encounter with the following problem:
LW3 in CNC mode, and latest version.

I am cutting a piece of 5mm wood and I put the final depth to 5mm with a 1mm depth per pass, the gcode generated start with Z0 and finish with Z-4.
The final Z value must be -5 mm, and the Start for Z must be -1, No?
When run the g code, always have 1mm less cut.