My fixed positioned div (#stoerer) appears to be moving while scrolling, although it is just an optical illusion. Check out this visual explanation: view gif for clarification
Below is the code snippet in question:
<div id="stoerer">
<button class="closed"><i class="fa fa-times" aria-hidden="true"></i></button>
<h1>OSTERSPECIAL!</h1>
<h2>EINMALIGE ANGEBOT ZU OSTERN</h2>
<a href="<?= BASEURL ?>angebote"><i class="fa fa-angle-double-left" aria-hidden="true"></i> Learn more</a>
</div>
#stoerer {
//display: none;
position: fixed;
right: 0;
top: 15%;
@include box_shadow(4);
width: 350px;
background: $mvBlue;
padding: 20px;
z-index: 999;
}