They inform me that the “reflect” command of the subDs is not updated when an extrusion occurs. Reflection occurs an edge, a face (even with the vertex reflection does not work), but if you extrude (a border or a face) the reflection does not take place immediately.
It will be a bug …
It appears we introduced this bug in the past week or so. We’re actively working on it.
https://mcneel.myjetbrains.com/youtrack/issue/RH-58357
Ok Dale, then it is a known bug (better a famous bug than an unknown one) 
Good job… you are good team!