We’ve encountered the same thing when trying to put a slider on the page designated as the front page. The behavior I’ve found to be the case is:

The [layerslider] shortcode works on all but the front page. The slider will have the stretching behavior that we desire – it will stretch as much as the browser allows it to, even beyond what is otherwise the site’s maximum width.

The [av_layerslider] shortcode works on all pages, but the slider will not stretch beyond the site’s maximum width as set in the Enfold theme settings. (However, if you put more than one layerslider using the av_ prefixed shortcude on one page, only the first will exhibit this behavior. The others will stretch out, which I think might have something to do with unclosed divs?

Clearly the shortcode not getting picked up on the front page is a bug. For the rest, it’s harder to tell where intention and bug might leave off or begin.

If using the Avia editor instead of the WordPress default, it works out as we want – we’re able to place a single layerslider on the page that stretches to the full width of the window. So that’s what we’re doing to compose our front page for now.