By default, transitions are disabled (set to "none") when you're either coming FROM or going TO a page where the scroll position is 3x the height of the device's screen. This feature was added because of the slow response times and the possibility of browser crashing when clicking on a list item (or any navigation element) far down a long page which leads to the browser trying to animate a really massively tall page from the scroll position to the top of the screen. The scroll position, not total screen height, is the determining factor for performance. This scroll position breakpoint is configurable via the new function.