Yes. That click box is layered over the small phone icon at the bottom right. Ideally, it should prevent the phone from flying up until the user clicks the click box. I've found a temporary work-around, by duplicating the slide and using the click box action on the first, and allowing the phone to fly in automatically upon entering the second slide. This seems to work, but Ideally, I'd like to figure this out. Any suggestions regarding my Click box at 1 second that seems to be the...Cause of the Pause? 
D&D is designed really to have only that interaction on the slide, that is my experience. If possible use two slides, where the first has that phone with its click box, that will release the effect when clicked. You have even more happening on that slide, besides the D&D because I see objects coming in a staggered way with effects. Keep the interactivity on a separate slide, all Drag sources and Targets need to be present from the start of the slide. You can always time objects (not the D&D objects) for the rest of the project so that they appear on the second slide (but you'll have to hide them on the slide after the D&D). D&D slides act a little bit like Quiz slides, which do allow even less customisation.