Edit text on canvas not working for localisation

When my client tries to edit content on the canvas directly for elements that are not dynamic, it always shows the primary language (FR) eventhough before entering into the “edit mode” he switchted the language to EN. (he wants to edit the EN translation…)

What can I do ? Do we really have to have dynamique collection for all texts so that the user can modify translations through the CMS instead of directly onto the canvas ?