Cancelling block drag in IE breaks canvas functionality.

I'm seeing this issue locally and on the GrapesJS demo when using Internet Explorer. If you drag a block over the canvas and attempt to cancel the drag by either dragging the block back to the starting container, or by pressing escape, a new component is still added to the canvas and the canvas highlighting and toolbar stop working. Dragging another block onto the canvas without cancelling it restores the functionality. Expected Behavior: After dragging a text block over the canvas, pressing escape or returning the block to the block menu should not add a component to the Editor. Actual behav...