I think I understand this now and as weird as it is, The facing operation is working correctly.bill wrote: However, the bottom face has some issues for me. Investigate extending the passes in Mill Facing:Operation tab.
cal.png
In issue #2484, If the underlying operations don't produce any Path, the job continues to show the last path that it rendered. So if you delete an operation, the old path still shows. In this case, when the operation is first created, it defaults to the Job's base model perimeter and produces the path shown. If you select the lower face only, the large 50mm facing mill doesn't fit inside so it doesn't produce a path. but the old path still shows.
If you set the pass extension a little bigger or use a smaller tool, then the path renders correctly.