Hi Norbert,
I have built your code and can reproduce the behaviour you describe:
using overload 1 and clicking on all 3 symbols I get the topomost graphic e.g. the advanced symbol:
identifyResults.size= 1
[[[ iResult= Esri::ArcGISRuntime::IdentifyGraphicsOverlayResult(0x266776516b0) (#Graphics within result= 1 ) ]]]
retrieved AttrVal= ""
using overload 2 and clicking on all 3 symbols I get just the simple marker symbols:
identifyResults.size= 1
[[[ iResult= Esri::ArcGISRuntime::IdentifyGraphicsOverlayResult(0x266774181f0) (#Graphics within result= 2 ) ]]]
SimpleMarkerSymbol
retrieved AttrVal= "drawPictureMarker:r=10"
SimpleMarkerSymbol
retrieved AttrVal= "drawPictureMarker:r=20"
I will see if I can come up with a simpler repro using our latest version and log a bug.
Thanks for reporting this!
Luke