Hi Barryd
this is clearly a bug.
@Shapr: the original sketch is modified when doing extrusion with negative draft angle, even if we lock it previously to the extrusion. (Positive draft angle does not trigger the issue).
This shows that locked sketches can be modified, which obviously is not the expected behavior.
I still don’t fully understand what you are doing with sketches when we extrude bodies. Looks like you are recreating the locked sketch by projecting the body to the sketch
@Barryd: a work around is to move the ellipse to a new location, and then move it back to the original location. This will hide the problem.
Best
PEC