plotly.py: px animations does not show correctly colors if all colors are not in the first frame

For example

import pandas as pd
import plotly.express as px
dataVals = {
    'Lat': [39.783730, 7, 39.783730, 39.783730, 20, -4.03, 39.783730, 36.82, 39.783730],
    'Lon': [-100.445882, 66, -100.445882, -100.445882, 70, 5.33, -100.445882, -1.29, -100.445882],
    'Value': [40, 12, 22, 3, 60, 23, 30, 100, 200],
    'Year': ['1985', '1990', '1990', '1990', '1990', '1990', '2000', '2000', '2000'],
    'Continent Color': ["a", "b", "a", "a", "b", "c", "b", "d", "a"]
    }
data = pd.DataFrame(dataVals)

fig = px.scatter_geo(data, lat="Lat", lon="Lon", size="Value", color="Continent Color",
                     animation_frame="Year", animation_group="Continent Color",
                     projection="natural earth", size_max=200)

fig.show()

(all points are displayed with the color of continent “a”). Reported by https://community.plot.ly/t/scatter-geo-only-shows-values-with-a-certain-color-if-i-have-multiple-years-as-the-same-year/35976. Other functions such as px.scatter have the same problem.

If all colors are used for the first frame, the problem disappears.