i see youre using a custom phone grid.
make sure the css for the splitscreen website is in "custom css for desktop version".
so basically, make sure the css that currently works for you is not in the "custom css" field, but make sure its in "custom css for desktop".
then, add this in "custom css for phone version":
body>.lay-content #custom-phone-grid,
body>.lay-content #footer-region {
height: 100%;
position: fixed;
top: 0;
overflow-y: scroll;
overflow: -moz-scrollbars-none;
scrollbar-width: none;
-webkit-overflow-scrolling: touch;
}
body>.lay-content #footer-region {
left: 0;
width: 50%;
}
body>.lay-content #footer{
box-sizing: border-box;
min-height: 100%;
}
body>.lay-content #custom-phone-grid {
right: 0;
width: 50%;
box-sizing: border-box;
}
::-webkit-scrollbar {
display: none;
}
basically its the same css as for the desktop version, but since you're using a custom phone grid layout, were using #custom-phone-grid instead of #grid