Main menu won't translate into French (France)


I run an OJS instance with some 20 journals
I’m preparing a new journal in which a cannot make the primary menu to translate into French (France). Despite I see all of the UI elements translated into French when I select this language at the front-end, the menu wont’ come up into French. It remains in Spanish (primary language)

I have the following language configuration for this journal:

  • Spanish (primary, all options set)
  • French (France), (UI, Forms, Submissions)
  • English (UI, Forms)

If I activate French (Canada), and select it in the front-end’s sidecol, the main menu will display in French correctly. But this won’t happen if I select French (France).

All the journals which use French in my OJS use the Canadian variation. I have activated French (France) in another journal, and main menu won’t translate either.

Any idea to solve this issue will be appreciated.
Thanks in advance for your reply.