Empty Poligon in Choropleth

I am trying to create a choropleth chart:

import json
import pandas as pd
import plotly.express as px

county={"type": "FeatureCollection", 
                  "features": [
        {
            "type": "Feature", 
            "properties": {}, 
            "geometry": {"type": "Polygon", 
                         "coordinates": [[[7.75, 47.1], [7.75, 47.3], [7.25, 47.3], [7.25, 47.1]],
                                         [[9, 47], [9, 47.5], [8, 47.5], [8, 47]],
                                        ]}, 
            "id": "01017"
        }, 
        
                  ]}
d = {'fips': ['01001','01009','01017'], 'unemp': [0, 6,12]}
df = pd.DataFrame(data=d)

fig = px.choropleth_mapbox(df, geojson=county, locations='fips', color='unemp',
                           color_continuous_scale="Viridis",
                           range_color=(0, 12),
                           mapbox_style="carto-positron",
                           zoom=7, center = {"lat": 47, "lon": 8},
                           opacity=0.5,
                           labels={'unemp':'unemployment rate'}
                          )
fig.update_layout(margin={"r":0,"t":0,"l":0,"b":0})
fig.show()

The square on the right hand is not filled and I cannot figure out why.