【Question】why dragend event triggers after the ghost animation finish? #2428

I find the dragend event fire after the ghost animation finish

I jump in the source code and find the following code

on(ownerDocument, 'mouseup', _this._onDrop);

see https://github.com/SortableJS/Sortable/blob/master/src/Sortable.js#L629

I thought when I release the mouse, the onDrop can be called
but somehow, it is not triggered

can any one help with this?
thank you so much