Starting in GP Premium 1.7, the Full Screen option is only available when Merge with content option is selected. The reason is because Full Screen without having the header merged required javascript and was a little hacky, and it』s not truly full screen if the header isn』t merged.
However, if you would like to size the page hero so it fills the rest of the space below header and navigation, simply add the CSS snippet below:
.page-hero {
min-height: calc(100vh - 200px); /*Modify the 200px to the height of your header*/
}
Don』t know the height of your header or navigation? Start a support topic here and we will be happy to help you out