Jumpy page on mobile phone

Hello i have installed the cafe demo but have replaced the revolution slider with canvas slider with this markup after the header:

<section id="slider" class="slider-element force-full-screen swiper_wrapper full-screen clearfix">
    <div class="swiper-container">
        <div class="swiper-wrapper">
            <div class="swiper-slide dark" style="background-image: url('images/main/inside-asian-spice-tandoori-dark.jpg'); background-position: center top;">
                <div class="container clearfix">
                <div class="slider-caption">
                <h2 class="display-2 mb-0 color">Asian Spice</h2>
				<h3 class="mb-2">Tandoori Restaurant</h3>
                <p data-animate="fadeInUp" data-delay="200">Dine in space for over 100 diners! Perfect for any occasion call: <a href="#">0118 945 5595</a> or <a href="#">0118 945 3334</a></p>
				<a href="#section-reserve" class="button button-border button-rounded button-large button-light" data-scrollto="#section-reserve" data-offset="5">Book a table!</a>
                </div>
                </div>        
            </div>
        </div>
    </div>
</section>

This is fine on big screen browsers and even responsive design mode, but on real mobiles there is a jump when I scroll down. You can see a live version here:
http://webdm.co.uk/ast/

Maybe I have an extra class somewhere that is causing this, I tried the to clear it with the <div class="clear"></div> but that didn't solve it.

Cheers

Great yep that sorted it, will removing this line cause any other issues?
Thanks