Z-axis cuts to deep on first pass

I recently calibrated my x-carve. The interesting part is that when I use the probe for setting the z-axis it cuts too deep on the first pass, and when I manually set the zero its fine. The odd part is that when I set up the machine, the disk thickness matches what it says in easel. So I’m just not sure why when both the machine and the probe are calibrated correctly, it’s cutting so deep on the first pass.

Ours did this at the school. Before even moving it bored through the material, wasteboard, and buried the collet before we hit stop. Tried again after resetting probe thickness and it cut a line on the way to the pattern. Never figured it out other than it appeared to me that the computer thinks its 358 inches higher than material. Anyhow, we don’t have issues when zeroing manually so thats what we do.

It’s an odd problem. I guess I’ll just measure how much extra it cutting and add that distance to the height of the disk and hopefully that works.

I was nervous I’d have the same issue on the one I just finished for home. No issues at all, maybe I’ll be able to compare the two and see if I can find a difference