Yep, the button is inside a form for some reason. Changing the form to a div fixes the problem.
Oddly enough, clicking the button placed in the right pane doesn't do this because it isn't inside a form. Strange that there's a form on the left but not on the right.
Comments
Nice proof of concept.
One bug I noticed: Accidentally clicking the submit button when trying to drag it will submit a form and cause you to lose your work.
Yep, the button is inside a form for some reason. Changing the form to a div fixes the problem.
Oddly enough, clicking the button placed in the right pane doesn't do this because it isn't inside a form. Strange that there's a form on the left but not on the right.