Responsive slider question

I’m wondering if anyone can offer some insight into this, if this is even possible. I’m working on a new responsive site for my workplace and I’ve used the Freestyle stack to create a slider on this test page:

The slider contains 2 slides visible at a time which cuts down to 1 side on smaller screens (more will be added later). I’ve input the proper height of the slide into the stack and it all works EXCEPT the “medium” devices, like a portrait iPad or a landscape iPhone. Instead of scaling down to fit both slides in, it renders the slider at 100% and cuts the second slide in half.

I know I can work around it by creating a second slider that is manually scaled down only for medium devices, but before I resort to this I wanted to make sure I wasn’t doing something wrong. Thanks!