wrong information for linked WF when creating a box element container

6.0 r22542

I have created a box and defined for it a specific WF (jahia std)
Then I add an element in my box, and switch to tools tab, WF section. It as a linked WF, but it is indicated that it is linked to the page n-step WF, whereas it should be the box's one, as it the parent container.
I validated my container creation, and then edit it: it has been well created, its WF is linked to the box's one