category order bug

[nicolaskruchten]

This pen https://codepen.io/nicolaskruchten/pen/OJXrOLG shows (on my machine anyway) the categories being out of order:

reported in plotly/plotly.py#2350 but oddly not always reproducible.

[archmoj]

Here is a minimal codepen.

[archmoj]

Strangely trace 1 displays no A although it has some: codepen.