Phplist v3.6.0 - Curious behaviour with lib.php in french

Hi All,

I’m still working on french version of Phplist v3.6.0.

I noticed a curious behaviour with lib.php.
System messages are correctly translated in french. We can see them in the browser with “View source”. But english messages are displayed on the screen by the application.
I really don’t know what happens. :stuck_out_tongue:
Any idea?
Here you are the source:

Thanks in advance