Page Contents Fades Out After 1 Second

Question

I have an website that a modal. Whenever I visit one page, however, only on a mobile device, all the content fades off the screen after 1 second of being there. I am using backstretch.js, and this exact HTML: <div class="modalDialog"><div></div></div> is required to be on the page, in order for the content to stay. My CSS for the .modalDialog class looks like this:

.modalDialog {
    -webkit-transition: opacity 400ms ease-in;
    -moz-transition: opacity 400ms ease-in;
    transition: opacity 400ms ease-in;
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: rgba(0,0,0,0.8);
    z-index: 99999;
    opacity:0;
    pointer-events: none;
}

Is there anything in this CSS that would be causing this? Thanks!