Map is not drawn in a multi-map app when GraphicsOverlays are used

[VolkerMatzken]

In a multi-map application, when an area is drawn on a graphics overlay, the background map is no longer displayed, instead you see a strange combination of letters and graphics.

The application layout is as follows: Multiple map instances are active on different user controls. Each map user control is isolated from the others and has its own graphics overlays, graphics are not shared between map instances.

The following procedure always leads to this state:

1: Draw point and area graphics on graphics overlays on Map1.
2: Open Map2 in another tab, also draw point and area graphics on Map2
3: Switch back to Map1, draw point and area graphics, the graphics overlays are drawn but the actual map is no longer drawn.

Please, see also the short video attachment.

This happens on multiple workstations with different graphics cards. The app is compiled against ArcGIS Runtime .NET 100.8. The app ist a successor of our Runtime 10.2.7 application, the Graphics-Overlay part was completely rewritten since we used Graphics-Layers in the previous version.

Does anybody have an idea what is happening here or how one could get behind it?

Many thanks for any hint in any direction and have a great day.

Volker

[dotMorten_esri]

That looks like a marker symbol texture ending up on the map somehow. That's definitely a new one. 
Any chance you can make a small reproducer ? I think we'd need to debug this issue to understand how this could happen.

[VolkerMatzken]

Thanks for the clarification, I now suspect the labeling to be the cause. The application is very complex and I haven't really had the time to take a closer look, I'll try to find out more over the weekend and maybe I'll be able to build a repro.

[MichaelBranscomb]

Hi,

Please can you retest with the latest release (100.9) and let us know if you can still reproduce?

Thanks

Mike