title: Plotly pie graph not showing all data
body: <p>I have noticed that my go.Pie graph only shows 2 of the 3 values held in the dataframe column. I noticed this when creating a px.treemap referencing the exact same column in the dataframe and it shows all 3 values.</p>
  <p>Below is my code for the pie chart and then the treemap</p>
  <pre><code>#docCategory count pie graph
  valuesDocCat = df['docCategory'].value_counts()
  figDocCat = go.Figure(data=[go.Pie(labels = df['docCategory'], values = valuesDocCat)])
  figDocCat.update_traces(textposition = 'inside')
  figDocCat.update_layout(uniformtext_minsize=14, uniformtext_mode='hide', title='Document Category breakdown')
  
  #treeMap test graph
  valuesTreemap = df['Kind'].value_counts()
  figTreemap = px.treemap(df, path = ['docCategory', 'Kind'], color='docCategory')
  figTreemap.update_traces(root_color='lightgrey')
  figTreemap.update_layout(margin = dict(t=50, l=25, r=25, b=25)
  </code></pre>
  <p>You can see my code above referencing the <code>df['docCategory']</code> in both instances but as you can see in the images below the pie chart doesnt have the 'Unknown' field whereas the treemap does.</p>
  <p>Any ideas on why? I have other pie charts that have more than 2 fields being referenced and no issues, it is just happening on this one.</p>
  <p><a href="https://i.stack.imgur.com/j2BRL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/j2BRL.png" alt="piechart" /></a></p>
  <p><a href="https://i.stack.imgur.com/AfJ34.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AfJ34.png" alt="treemap" /></a></p>