Issues with Line Appearing using Zoom Region

I am attempting to focus in on a portion of a title slide to convey we are moving on to a new topic. When I add a zoom region, all works as planned, but a thick white line shows once the zoom completes. That white line is nowhere to be found and does not show without using the zoom feature. Has anyone experienced this before & may know how to fix it? 

I added a photo of the slide before and after zooming.