Home page fullscreen slider on mobile devices

Hi
I searched the forum and found a number of issues related to the fullscreen slider display issues on mobile devices.
I tried the following in my quick Enfold general styling quick CSS but nothing changes:

@media only screen and (max-width: 1366px) {
    .avia-fullscreen-slider .avia-slideshow[data-image_attachment="fixed"] > ul > li {
        background-attachment: scroll !important;
    }
}
@media only screen and (max-width: 1366px) {
    .flex_cell {
	background-attachment: scroll !important;
    }
}

@media only screen and (max-width: 768px) {
.avia-fullscreen-slider .avia-slideshow[data-image_attachment="fixed"]>ul>li {
background-attachment: scroll;
}}

@media only screen and (max-width:767px) {
  .responsive #top .avia-slideshow-controls a {
    display: block !important;
    opacity: 1 !important;
  }
}

What happens is that I don’t see my slider images nor the slider controls.

My website is in development so not yet visible to the public. I have included the login access credentials below so you can see for yourselves.

Any insights would be greatly appreciated.
Lyse