Hi, this worked for me:
.head-bg,
.home-feature-1,
.home-feature-2,
.home-feature-3,
.home-feature-4,
.home-feature-5,
.home-feature-6,
.home-feature-7 {
background-attachment: scroll !important;
-webkit-background-size: cover !important;
-moz-background-size: cover !important;
-o-background-size: cover !important;
background-size: cover !important;
background-repeat: no-repeat !important;
}