Subject of the issue

Draggable cancel does not work when element specified is placed within a web component (and within shadowDOM).

Your environment

gridstack v10.2.1 (as per demo fiddle for issues)

Steps to reproduce

Please see the below jsfiddle for example of the bug/missing feature
https://jsfiddle.net/churnthatmagma/6qvp0sth/14/

Expected behavior

Draggable cancel applies to any element even inside the shadowDOM tree