Issue with graphics in slide vs preview

Hoping to get some help with this. I've been using Storyline since version 1, and this is by far one of the most frustrating things that has been happening since I've been a Storyline user. Sometimes there is a discrepancy between what I build on the slide and what shows up in preview. It's small details, but definitely noticeable. For instance, I've attached two screenshots, one of the slide I'm building and one of the preview. Notice the tab at the top that reads 'Card 2'. In the slide build view, the bottom grey runs seamless. But in preview mode, there is a thin blue line, as if my shape isn't positioned correctly. I assure you the shape extends well past that line. Not sure what is up, but it is frustrating.