Question OTK use in UCCNC has random Z-axis glitch that causes Z axis to plunge deeper

I have a q804.

I have a strange glitch that happens when I run jobs. Randomly within the job the Z axis will go beyond the designated depth the G code is programed for. For example the code will be set to a cut depth of -2mm and on half the cuts the Z axis will plunge correctly to -2mm. The other half of the time it will plunge as deep as 5-6mm past 0. This is causing me all kinds of problems with my final parts, it's also risking blade damage. I should note that the GCODE says -2.000 but the readout of the actual location on the machine in UCCNC is going to -3.500 or more. It's most likely a software issue.

This seems to be an issue with extremely small short lines and not with long large cuts.

if anyone has any idea what this might be or has tips for OTK settings that would be super helpful.

I have a D600 V2 that has the same issue when engraving text (short lines of text) after carving the base. It randomly drives down and destroys the work. Almost looks like a machine memory issue or loosing steps during the job. I am also looking for any help in resolving this issue.

I'm pretty sure its losing steps, I had his problem with my machine too... my only way around this was to avoid plunge cuts all together... inconvient for sure, but simply put without the upgrade kit for the stepcraft, (which I dont have because they stopped making them right after I bought my machine) the machine cant tell or correct itself for lost steps. and apparently there is no alterative solution to the no-longer-in-production stepcraft upgrade kit unless you throw out thier motherboard all together (voiding the warrentee) and buy a new motherboard from a producer that includes motor sensor and step correction hardware onboard. and the end of the avoiding plunge cuts is just lazier and easier..