Formula are not visible on the Wikipedia/wikimedia visual editor

[gagarine]

On the visual editor formula disappear. For example on this page: https://fr.wikipedia.org/wiki/Multiplicateur_de_Lagrange If you go on the editor their formula are note visible: https://fr.wikipedia.org/wiki/Multiplicateur_de_Lagrange?veaction=edit

Note, I'm using this extension only to copy formula (with https://github.com/fred-wang/webextension-mathml-copy) as Wikipedia natively use MathML for modern navigator.

I'm using Firefox 63.

[fred-wang]

cc @physikerwelt who is more aware of the current status of Wikipedia.

[physikerwelt]

No clue. I filed an issue in phabricator https://phabricator.wikimedia.org/T209079