Need help with carve gone crazy

What do you think caused this. There are little lines that are not supposed to be there.

Looking at it closely, it looks like maybe it started over but offset

It looks like the machine lost steps along the way, causing it to offset up to the right.
Did the machine bump into an extreme end of its reach?

Was this a two-stage carve?

Did you run the simulate to see if you have any unwanted objects you cant see sometimes you get tiny element from imports that the machine will carve even though you cant visually see them.

It appears to be a two stage carve, have you gone through the steps to lock your motors? did anything move when you were changing bits? did you use last XY coordinate in you setup? whenyou went from roughing to detail pass?