I'm creating a script tool in ArcGIS Pro 2.7 which creates a number of point and polygon shapefiles, then draws them on the map using symbology from an appropriate layer file. Each shapefile has a 'Type' attribute that determines the symbology for each geometry in the file. I've attached the layer file I'm currently using to define polygon symbology.
Basically, I want Pro to draw polygons where 'type'='ss' as yellow, and polygons where 'type'='sk' as red. If a shapefile contains both an 'ss' and an 'sk' polygon, they are drawn as expected, but if there is only one polygon in a shapefile, it is drawn as red regardless of its 'type' value. What's confusing is that the layer's primary symbology is still acknowledged as 'Unique Values', and 'type' is still given as the value field.
The symbology is applied properly when I manually import symbology from the layer file, but when I point to the layer file from the script tool parameters dialog things go wrong.