PowerDesigner 16 PDM Model Options not enforced and randomly ignored

PowerDesigner Enterprise Architect
Version 16.0.0.3576 EBF5
OS: Windows 7 Professional 

PDM Model Settings are set as shown below:


When diagrams were created, reference symbols were as displayed below:



Randomly, PowerDesigner chooses to ignore these settings and changes ALL reference symbols in ALL diagrams to the "Relational" Notation:



When this happens, I have to open each diagram, right click in the diagram white space, select Model Options, change the Notation style to anything else, click OK, open the Model Options again and change the Notation style back to Conceptual.

PowerDesigner does not let me change the reference symbol format using Display Preferences when this happens.  All the options are grayed out and set to "Notation".

Sybase Inc. - Case Express bug opened:
Case Id: 11727628 - PowerDesigner randomly ignores Model Options reference setting