Highlighting Turns Off

Has anybody else noticed that the highlighting of entities turns itself off seemingly at random?  The last occurrence of this happened when I was running the erase command, I selected a couple entities and could see them highlighted, I then added more entities to the selection set by using the crossing window and normal pick a couple of times, all of the newly selected entities did not highlight as selected until I panned or zoomed.  I should maybe mention that the selected entities are standard lines, arcs and circles with no special properties.

I have checked the drawing using the audit command - no errors, the drawing was originally created in BricsCAD (including the template and all blocks that are used). The value of the highlight system variable is set to 1 if I check it using (getvar "highlight").  A restart of the application does temporarily reset the system to its normal behaviour.  I am running BricsCAD V14.1.05 (x64).  If I toggle the highlight variable there is no change when the value is again set to 1.