Issue with faceted browse translation

Hi! I’m currently working on an Omeka S website for Collège de France and I’m struggling with faceted browse. The problem is quite simple: facets are set in French (screen 1) but appear in English on the site (screen 2) . Same thing for “Resource classes” by the way. (screen 3)
!
Is it a well-known issue? Any tips?
Thank you !

Screen 1
Screen 2
Screen 3

We discussed this on the French community mailing list. I cannot reproduce this. It appears to be related to a custom theme.