Subject of the issue

I am building form builder using gridstackjs, so users can drag form element from outside inside the form, and move/resize inside the form.
<input type="text"/> cannot be draggable if it has parent div,
I also noticed normal div cannot be dragged if it has parent div.

Your environment

I am using v3.0.0, and tested on html5 native dnd.

Steps to reproduce

Here's demo you can reproduce - https://jsfiddle.net/cwrjq5z3/9/

Expected behavior

Input should be able to be draggable no matter it has div as parent or not.

Actual behavior

Input is not dragged when it has parent div