Strange Behavior in Borders of Player

This is odd. I have a 10 scene project at 110 x 640 pixel but one of the scenes (quiz) is forcing a wide margin on both sides of the player. I've never seen anything like this. If I preview each scene individually they all have the proper player borders except this one. When I publish or preview all scenes this problematic one is causing the border to be too wide for the entire project. There is nothing off-screen in the offending scene. Any suggestions why this is happening and how to make it stop?

Here is the odd border: 

And here is how all the other scenes (properly) look: