I have one project for which the xPub export refuses to include the French localization, despite it being selected in project settings. When I open the file in Pubreader on both iPad and Galaxy tablet, and use the flag option to select available languages, French is not an option in the list. All my other projects successfully export all localizations selected. I can't see any reason why this one isn't behaving properly. Does anyone have any suggestions as to what I could check?