NX Reference Curves disappear when exiting or finishing the Sketch

While in an active Sketch, hover the cursor over the curve, 'MB3-->Convert to Reference'.
Now Finish or exit the Sketch.
The Reference Curves are disappearing.

To set a Sketch preference so any new sketch features will display the Reference Curves after the Sketch feature is finished:

1. In the Menu, select 'Preferences-->Sketch'.
2. Select the 'Sketch Settings' tab.
3. Toggle 'Display Reference Curves = ON'.
4. OK the Sketch Preferences dialog.

To turn on Reference Curves from existing Sketch features:
1. In the Part Navigator, highlight the Sketch feature, 'MB3-->Settings'.
2. Toggle 'Display Reference Curves = ON'.
3. OK the Sketch Settings dialog.