I know, this has been discussed over and over again. but it still seems to be a specific understanding issue on my side. after implementing several bug fixes from here and elsewhere my site is still not working as wished. I got a fixed background-image in the header section of my page. this is working perfectly fine on normal chrome browser. however i cannot get it running on mobile chrome browser
i've got following lines of html:
<body id="page-top">
<!-- Header -->
<header class="masthead bg-head text-white text-center">
    <div class="container">
        <h1 class="text-uppercase mb-0">My Name</h1>
        <img id="header-star" class="img-fluid" src="img/star-light.png" alt="">
    </div>
</header>
aligned with the following lines of css:
body {
    font-family: 'Lato';
    max-width: 1280px;
    margin-left: auto;
    margin-right: auto;
    background-color: #fff;
}
header{
    background-color: #4a4a4a;
    background-image: url("../img/background-bern-4.jpg");
    background-attachment: fixed;
    background-repeat: no-repeat;
    background-position: center top;
    padding-top: 6rem;
    height:500px;
}
for example i wrote a media query with height of 100% with browser specific commands and so on:
@media (max-width: 576px){
    header{
        height:100%;
        background: url(bg.jpg) no-repeat center center fixed;
        -webkit-background-size: cover;
        -moz-background-size: cover;
        -o-background-size: cover;
        background-size: cover;
    }
}
and then i tried to put y-overflow: scroll; to body and hidden to header enter link description here
Furthermore I tried to put the image into a div like this enter link description here html:
<!-- Header -->
<header class="masthead bg-head text-white text-center">
    <div class="container header">
        <h1 class="text-uppercase mb-0">My Name</h1>
        <img id="header-star" class="img-fluid" src="img/star-light.png" alt="">
    </div>
</header>
css:
.header{
    position: fixed;
    z-index: -1;
    background-color: #4a4a4a;
    background-image: url("../img/background-bern-4.jpg");
    background-attachment: fixed;
    background-repeat: no-repeat;
    background-position: center top;
    padding-top: 6rem;
    height:500px;
}
whit this technique the picture is gone completely after all

somewhere I must missing something, don't I?
