I was fixing French video links when I noticed some video links appearing in the "French" list (filtered with "French" as a language) were actually about songs in other languages (Romanian, Arabic, you name it).
Of course I could not fix these vids since I have no clue about these languages and could not even check the titles.
After fixing a few genuine French vids, I ended up with a list consisting entirely of links I could not fix.
I seemed to notice such "wrong" songs appeared when the link had been posted from a French translation page.
My guess is that the filter gathers links from the translation pages (as it should - people might give a valid video link from a translation page alright), but assigns to the vid the language of the page where it was found.
For instance, a vid linked from the French translation of a Romanian song would end up in the French list instead of the Romanian one.
Assuming I did not hallucinate, I guess the correction is pretty straightforward (picking the original language from the translation page and using that to sort/filter vids by language).
I wonder if other editors have already experienced similar problems, or if I have just missed something ?