Hi TarynPierce this is expected behaviour. Whilst Storyline "scales" in size, maintaining it's aspect ratio as it does scale, Rise is "responsive" and will adjust position of elements and maintain the size of those elements across all devices. There is a fundamental difference how these courses work on different device sizes.
For example, if you design a Storyline course at 4000px by 1000px. This is an aspect ratio of 4:1, and so if your screen width is 400px the height of the Storyline file will be 100px.
Rise is fully responsive and will adjust the content to suit the device. It does not have a fixed aspect ratio.