I have created a demo (not in Jsfiddle, couldn't get it to work in device):
http://i283951.iris.fhict.nl/test.html
When I open this on my iPad and scroll down all the way and then click on the input, it scrolls all the way up to the top and then shows the keyboard.
I'm pretty sure this also happens with a iPhone, on my android I don't have those problems. So I think it's iOs related.
body {
margin: 0;
padding: 0;
height: 2000px;
}
.top {
width: 100%;
height: 50px;
position: fixed;
background-color: #AA3939;
}
.input-group {
margin-top: 12px;
margin-left: 50px;
}
<html>
<head>
</head>
<body>
<div class="top">
<div class="input-group">
<input type="search" placeholder="Search...">
<button type="submit">Submit</button>
</div>
</div>
</body>
</html>