Bug report

The results of the sankey plot on the gallery seems broken: https://matplotlib.org/devdocs/gallery/specialty_plots/sankey_basics.html#sphx-glr-gallery-specialty-plots-sankey-basics-py

Running the code on my computer produces a different result: why it is rendered like this on the gallery needs to be investigated.

Edit: it is not the only plot behave this:
https://matplotlib.org/devdocs/gallery/specialty_plots/sankey_rankine.html#sphx-glr-gallery-specialty-plots-sankey-rankine-py