Symbology fails to draw in Map Viewer when publishing a referenced map image layer with a join between a standalone table and spatial layer in two separate geodatabases from ArcGIS Pro.
After publication, manually edit the symbology in Map Viewer as the attribute table is still present.
Place the standalone table in the same database as the spatial layer. This issue only seems to occur when the standalone table and spatial layer are separated.
Symbolize a field from the original spatial data instead of the table.