Sendy still using old translation po file instead of modified one

Using poedit, I have modified the default.po french translation file and saved it over the older version. The strange thing is that Sendy still displays the old text containing the very errors I corrected. Even when searching for those faulty texts in the updated po file, I can't find them, confirming that the po file present in the fr_FR folder is the updated one.

What am I doing wrong?

Thanks.