Wrong site language

Hi!

Just install your plugin to translate in french the plugin Use-your-Drive.
I’ve set my WordPress in french. Dashboard is in french, in database the WPLANG is “fr_FR”, but you’re plugin say that my site is in english. I check in the WP general settings and the language is as well set in english, despite my dasboard and DB are in fr_FR.
I’ve a couple of string in my DIVI theme which are in english in my french child theme.
I’m confused… Any idea?

Regards,
Dom