Plot areas in ArcGIS on Juypter

I’m trying to plot a filled area from an sdf, but no matter my settings, I seem to just get an outline of the shape with a green dotted line.

I’ve tried with a code sample from https://developers.arcgis.com/python/guide/visualizing-data-with-the-spatially-enabled-dataframe/

from arcgis.features import FeatureLayer
fl = FeatureLayer("https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/2")
county_sdf = fl.query("STATE_NAME='Washington'", out_sr=4326).sdf
county_sdf.head()

m9 = gis.map('Seattle, WA', zoomlevel=6)
m9.basemap='gray'
m9


county_sdf.spatial.plot(map_widget=m9,
                        cmap = 'RdPu',  # use a red to purple color map
                        symbol_type='simple',
                        symbol_style='s',
                        outline_style='s',
                        outline_color=[0,0,0,255],
                        line_width=1.0)

I get this image:

I’m looking for a filled-in shape of the state. What am I doing wrong?