Cutting just above surface

I don’t know if anyone else has had this problem, but I’m finding that with Chilipeppr when I run an auto-leveled PCB cut the bit is following the path, but just a hair above the copper.

Would could cause this?

I’m running a probe and then zeroing at the probe trigger heigt. It happened several times, then I went and watched tv all defeated, then went and tried one more time and it cut fine. I have no idea what could have changed.