Correcting beginning of Prezi Presentation - how do you delete an unwanted zooming in presentation?

When I click on to watch my Prezi on either my Mac or PC laptop instead of showing the full screen with all the frames it briefly shows an enlarged portion of one of the frames and then immediately corrects itself and begins with the the full screen. I do not have this problem when I watch the presentation on my iPad. How do I delete/correct the brief showing of the enlarged (zoom) portion of one of the frames that appears at the beginning of the presentation? I have no idea how it happened.