Drag and drop (Angular JS) In web browser not working

I am using UE 4.16 release.

In the Widget blueprint, I created two URLs that will load different URLs of angular JS drag and drop functionalities.

In the URL 1, When I click and drag the container 1, It will disappears. Here are some of the screenshots and the URL ( Drag & Drop Lists for angular.js ) of it. **



Here is the URL 2, ( Drag and Drop Demo )**

I also tested in the Mozilla, chrome, IE, Opera. It’s working perfectly fine.