Fullscreen canvas shrinks to half size in build only?

![alt text][1] The purple overlay is supposed to look like this, and this is how it does look in the editor. However, when I build and run, it becomes this: ![alt text][2] I have no idea why this is happening, and it doesn't happen when I load a different level in the same game with the same mechanics. I've noticed it's not just skrinking that canvas, but all three canvases I have in the scene. What's going on? How do I stop this from happening and make the canvas remain the correct width? [1]: /storage/temp/60339-untitled.png [2]: /storage/temp/60340-u2.png