In https://fr.wikipedia.org/w/index.php?diff=113669090 there were many <span lang="fr-FR"> tags added, even though it's on the French Wikipedia. This looks like T71494 but I'm not sure it's exactly the same issue. One cause might be the mix of French and English text.
See also https://en.wikipedia.org/w/index.php?diff=656444224 with <span lang="EN-US"> on the English Wikipedia.