Problems drilling only

I was cutting a project and used the drill function the other day. It was a simple drill in steps and move to the next hole. The holes were spaced about 10” apart. When each hole was completed the z axis was raised and the sled began to move. However two things happened. The z move didn’t raise to clear the material completely before it began the horizontal movement cutting between a 1/10 to 1/4“ slot in the material and it continued to raise until it reached the next drill point. Four holes, four streaks.

Drilling is the only time I have seen this behavior. I’ve not had this happen when performing cuts to create separate pieces. Has anyone else had this happen? If so what was your solution? In the meantime I’m not going to perform any more drilling.

Ground Control latest version
Firmware latest version
Estlcam v11

I looked at the gcode and even added a pause (G4) using P, X, and U and none of them worked. Is G4 used in GRBL? 4 wheels, 4 tests.

I have seen it before yes, when I was drilling holes in my backing board for a mounting system I put together.
The problem turned out to be that the standard Z axis wasn’t retracting properly, which I resolved with a bungy cord. Problem gone.
I really should upgrade the Z axis to a Meticulous.

This might have something to do with the vertical feedrate? If the z-axis is commanded to move faster than it can actually move it might not have time to fully retract before making the next move.

I considered that. I added a G4 S5 command After the initial command to raise the z-axis which appeared to be ignored. I’ve also noticed that there is other movement of the z axis during other moves such as between cutting holes. The difference was that this movement was above the cutting surface.