First Carve Issues Today

First carve didn’t go well. The first few passes had no issues and then machine started cutting away from the design. I tried two cuts and each time the machine made a noise like it had a hiccup and began to carve incorrectly from the image. The 2nd carve I let continue and it eventually plunged the bit into the wood.

The attached picture, the carving on the left is the first and the second one on the right.

Looking for possible solutions to fix issue.

Thanks

You are loosing steps, question is why.

Xcarve (I assume it is since you have Xcarve spoil board) or other machine?
Bit information, RPM and feed rate + depth per pass.
Do the machine jog okay all around its work area?
Do each axis actually move 10m if you send a 10mm jog in either direction?

I am going to guess that your Z axis pulley is not tight on the screw. Check the grub screws.(set screws)
Or you have selected the wrong Z screw during machine set up.