Highlighting after upgrading from OCCT 7.3 to 7.4 not as expected

Hello,

after upgrading from OCCT 7.3.0 to OCCT 7.4.0 the manually triggered highlighting of an AIS_InteractiveObject does not work as before.

The following code snipped shows, how I trigger the highlighting manually.

AIS_InteractiveContext aContext;
AIS_InteractiveObject aObj;
...
// manual highlight in red
Prs3d_Drawer aDrawer;                
aDrawer.SetColor(Quantity_Color(Quantity_NameOfColor.Quantity_NOC_RED));
aContext.HilightWithColor(aObj, aDrawer, true);

Attached are pictures of the resulting highlightings.

After upgrading to OCCT 7.4.0 

   - it's not highlighted in red anymore but in white/grey and

   - it's highlighted with iso-lines.

Why is that? And more important, how to get the red highlighting without iso-lines back?

Furthermore, I found this: https://www.opencascade.com/content/face-boundary-aspect-v740,  which is similar to this problem, but I couldn't handle it.

Regards,

Matthias