The ZIndex property change is not detected by the VisualizationLayer at runtime.
Workaround: remove and then add back the item where the ZIndex is changed.
Setting IsFilled property of the MapPathFigureView to False has no effect. The figure is not shown at all. The workaround is to use MapShapeFill and set Fill = Transparent. The XAML team has recently reviewed this issue and will not be addressing it as at this time the team is focusing on the bugs impacting the highest number of developers. If you have encountered this issue and it is blocking for your work please contact us through the support ticketing system with details on your setup and a reference to this item.