Determine why 'block:drag' event won't fire

My company uses GWT (Google Web Toolkit) to develop some web applications. We have a stand alone GWT component library for our re-usable components. I created a component that wraps grapesjs and it works great.

However, when I import this library into an actual project and add the grapes editor to a screen, everything works fine except dragging blocks onto the canvas. After diving into the grapesjs code, I found that BlockView::handleDrag() is not being called. BlockView::handleDragStart() does get called however. BlockView::handleDragEnd() also does not get called.

Is there some way I can possibly check what would stop the drag event from firing? This is the only code in the handleDrag() function:

  handleDrag(ev) {
    this.em.trigger('block:drag', this.model, ev);
  },

So it seems that Backbone is not publishing the actual browser drag event.

Thanks!