oh, it’s now working there was no link to the media file in the admin -_-
but for some reasons it was working on invidual image with a “classic” page load.
i’m a bit confused because when I compare the source code of the page generated with and without a dynamic load and it’s the same. there is no “data-lbwps-” attribute anywhere and I don’t know how I should add those. I’m a too bad developper to figure out what’s wrong but thank you for you answer 🙂