Group seems limited to 1290px width since recent updates

Hello.
Some updates occured end of last week (around 29/30 november), and now, a picture of a carrousel which was full screen width has its size reduced (to width 1290px).
Blocksy and its companion were updated and no other extension related to current issue (pretty much sure).

This is structure of the carrousel on top of the page :
Carrousel (from Stackable extension) contains 4 Stackable columns (because slideshow of 4 elements). Each Stackable column contains a “group” element from standard library of objects, and a Stackable column (for the text). The group contains a Stackable Image.

One could say “but isn’t it an issue with Stackable” ? I don’t think so for the moment simply because last update was 3 weeks ago and all was fine since then.

If I remove the group (and put directly the picture in the carrousel), it seems to work (but I need to keep the group for easier maintenance later).

In source code of the page, I see : stk-block-width-default-detected: 1290px;
This is exactly the reduced size of the picture. I wonder if this is pure coincidence or not…

In addition and interestingly, when editing the page, it looks with the right 100% screen width. The problem is only in user viewing mode.

Best regards.

The page I need help with: [log in to see the link]