Drag and Drop Interaction - Items to drag go away

I have created a drag-n-drop interaction in which the learner drags an item to the correct drop target, and that item spins and shrinks and disappears. I used this animation because I didn't know how else to  make the item disappear on drop.

However, all of the drag items spin and shrink and disappear after 15 seconds. I know this is because the timeline is 15 seconds in length.

How do I keep the items on the slide until the learner completes the this activity?

Please review the attached file.