Scattermapbox maki symbols plot on map, but not legend

Hi Plotly,

First, thank you for all the fantastic work you do.

I am a big fan of / heavy user of the plotly.go objects that render maps (Scattermapbox / Choroplethmapbox).

I have noticed, however, that when setting the symbol type to a maki symbol, it will render it on the map - but not the legend. This feels like a bug, as there is also a colour associated with the legend item that is not matched anywhere on the plot / by the symbol (except in hovertext).

Reproducible example below:

import os
import plotly.graph_objects as go

mapboxt = os.getenv('MAPBOX_TOKEN') # a mapbox token

lats = [52.370216, 53.2191696,  50.851368, 51.8125626]
lons = [4.895168,  6.5666699, 5.690973, 5.8372264 ]

fig = go.Figure()

scatt = go.Scattermapbox(
            lat=lats,
            lon=lons,
            mode='markers',
            hovertext=['Amsterdam', 'Groningen',  'Maastricht', 'Nijmegen'],  
            hoverinfo='text',                 
            below='',                 
            marker=dict(symbol ='hospital'),
            name ='my_fake_hospitals',
            showlegend=True)

fig.add_trace(scatt)

fig.update_layout(go.Layout(title_text ='Is it a hospital? No, it is a blue dot!', 
                            title_x=0.5, 
                            width=750, 
                            height=700,
                            mapbox = dict(center= dict(lat=52.370216, lon=4.895168),            
                                         accesstoken= mapboxt,
                                         zoom=5,
                                         style="light"
                                       )))

fig

Finally, as a side note, some maki symbols plot whilst others do not. I have determined through trial and error that this is down to whether or not the MapBox style includes these specific symbol types. Using custom Mapbox styles, therefore, may silently break the maki functionality as well.

Thanks you for your attention.

まず、Scattermapbox、Maki シンボル "hospital"、showlegend=True を使用した、提供されている再現可能な Python の例を実行し、次にマップのシンボルとその凡例項目を比較します。Mapbox styles に関する注記も含め、Scattermapbox の marker-symbol と凡例の処理を追跡します。対応する Maki シンボルが凡例とマップに一貫して表示され、その動作が回帰テストでカバーされれば完了です。