I received a KML file and wanted to convert it to a more ArcGIS friendly format. I used the KML to Layer tool in ArcGIS Pro 2.8. The process appeared to work successfully, but instead of all overlays showing up in my map, I only saw one. After some looking around, I found it correctly converted both rasters, but only one mosaic file.
In the short term, adding an explanation of this behavior to the KML to Layer help page would be helpful.
Ideally, the tool would be modified to treat all overlays the same, so create and add to map one mosaic per raster. Alternatively, prompting the user to select one, or even specifying what happened in a message in the appropriate tool run instance in History, would be helpful.