Sometimes I have some strange behavior when drag& droping objets on other objects.

It was as if sometimes the precede target of drag&drag (when it is cancelled ?) is used instead of the current one

For example, from a cart, I drag & drop a "city" content on another "city" content. There is no link possible between then, but when drop is effective, a dialog box is opened allowing to choose possible fields as if the target objet is a "structure" content.

Other example, after several drag & drop, a pop-up said me that there is no possible relation between 2 objets whereas the relation is really possible between them.