Swiper Does Not Load on Landscape for Phones

[pmacMaps]

I'm testing transitioning an existing shortlist app (v 1.4.4) to v 1.4.9. Using Google Chrome's dev tools, I've noticed that when I emulate a phone in landscape mode, the "Start" button appears on app load. Whenever this is selected, the map appears, but the swiper to change between tabs is gray and no text appears.

Whenever the app loads in portrait, the three tabs appear, and the app works normally.

This issue also occurs on my Moto G 1st generation in either portrait or landscape mode.

I know my app has had issues in the past (see #58).

I also have added two customization to the app. The first is a toggable legend and the second is some text which appears in the header.

The testing site is http://gis.ccpa.net/maps/labs/bridges/.

The current app is at http://gis.ccpa.net/storymaps/bridges/.