Omeka S + dl module : download options links to same image

[coolidfrez]

By using the dl plugin for mirador all the downloads options links to the same image (the medium format).

You can see the problem in action here : https://nubis.univ-paris1.fr/ark:/15733/n7bn

I can't find how to configure this.
Can you tell me how to set the links to the right images ?

thank you