null values reset stacking in express barchart #5324

It seems like null values in the middle of a series reset the stacking so that the next value starts at zero. I tried it upstream in a JS codepen and it is handled okay there, so I believe it is an issue with the python API or possibly with plotly.express.

Reprex modified from https://plotly.com/python/bar-charts/#bar-charts-with-text

import plotly.express as px

wide_df = px.data.medals_wide()

# set null value in middle 'silver' series
wide_df.iloc[0,2] = None

fig = px.bar(
  wide_df, 
  x="nation", 
  y=["gold", "silver", "bronze"], 
  title="Nulls Reset Stacking", 
  text_auto=True)

fig.show()

Output:

Based on input data:

Note that South Korea should be stacked to a total of 35 and not 24.