It kind of looks like you lost your Z setting while cutting. You don't say what CNC you are using so it might be belt slip if it has belts or could also be caused by the bit coming out or being pushed into the collet. might also be in the design file somewhere.
I would move the start point in between the faces so it is easier to clean up.
I would move the start point in between the faces so it is easier to clean up.