title: marker icon on plotly scattermapbox not updating
body: <p>I am using plotly's scattermapbox to render a map and trying to change the symbol. I have been using <code>circle</code> for point coordinates and need to update to a <code>marker</code> symbol instead. When i update the symbox in the code, the map defaults to circle.</p>
  <pre><code>data.append({
  
                          &quot;type&quot;: &quot;scattermapbox&quot;,
                          &quot;lat&quot;: df['Lat'],
                          &quot;lon&quot;: df['Long'],
                          &quot;name&quot;: &quot;Location&quot;,
                          #&quot;hovertext&quot;: rent,
                          &quot;showlegend&quot;: False,
                          &quot;hoverinfo&quot;: &quot;text&quot;,
                          &quot;mode&quot;: &quot;markers&quot;,
                          &quot;customdata&quot;: df.loc[:,cd_cols].values,
                          &quot;marker&quot;: {
                              &quot;symbol&quot;: &quot;marker&quot;,  | defaults to circle
                             # &quot;size&quot;: 18,
                              &quot;opacity&quot;: 0.8,
                              #&quot;color&quot;: &quot;black&quot;
                              }
                      }
          )
  </code></pre>
  <p></p>
  <p><code>marker</code> is a valid symbox based on the documentation here:</p>
  <p><a href="https://plotly.com/python/reference/scattermapbox/#scattermapbox-marker-symbol" rel="nofollow noreferrer">https://plotly.com/python/reference/scattermapbox/#scattermapbox-marker-symbol</a>
  <a href="https://labs.mapbox.com/maki-icons/" rel="nofollow noreferrer">https://labs.mapbox.com/maki-icons/</a></p>