floom is originally conceived to be hardcoded by hand in html page. The webmaster adds the js and css in header and lists the images to be ‘floom’ displayed. Cloning is here easy.
xili-floom-slideshow (XFS) plugin does a simple integration in the rich context of WP code and architecture. Currently, XFS activates the js and css at the right place according rules of WP. and keeps the images attached to the current displayed post (or page). The settings can be done in dashboard UI or in custom fields (meta) of the post containing the shortcode or a theme containing the div in header or elsewhere.
In your expected front-page, it seems that only one page is in the result WP loop, so XFS must choose the two slideshows according prefix or suffix of image’s filename ?
Or, is your front-page displaying two posts containing each one on slideshow ?
Consequences of the cloning in more than one exemplary is not without effects in how to code and improve the plugin.
The answer is not trivial and dive in coding will a little deeper so longer.
Be patient,