Ok. I have created a demo page here : http://nicheacademyspa.vteamslabs.com/widget.php
. Just click "open" button and after that try to drag the container through the "Resize" button. It won't. Now, try to resize using left edge of container, it will. After that again try to resize using "Resize" button and surprisingly, it will resize the container, although a little choppy. I hope i have explained the behavior. I was not able to recreate it on codepen.