Hi Guys hoping for some help on this one!
We use mach 4 for plasma cutting and most of the time it works great but a couple of times now we've started to have issues with the probing cycle. We're using build 4809 with Warp 9 ESS 285 smooth stepper and proma 150 THC.

At random blocks in our programs, the plasma cutter will suddenly read that it is at a Z height of 100" and then crash into the stock.

This is an example of the start of our G-code blocks when this happens:

G0 Z0.2
G0 X-2 Y4
G31 Z-100. F50.
G92 Z-0.4
G0 Z0

Once it reads that last G0 line, the Z readout in Mach4 appears to have been reset to 100, and the torch crashes into sheet trying to rapid down to Z=0.

This occurs at random blocks in otherwise functioning programs so its not fully repeatable but has happened a couple of times now.

We've made sure the probe switch is not worn down and is engaging properly to send a step signal.

I'm interpreting an error on the g92 step that instead of setting Z to -0.4 Its going to +100.

Any feedback would be appreciated!