Hi,

To do that, please add more this code:

/**
 * Filter favicon to make sure wp_site_icon() works fine also
 *
 */
if ( ! function_exists( 'penci_filter_site_icon_url' ) && get_theme_mod( 'penci_favicon' ) ) {
    function penci_filter_site_icon_url(){
        $favicon_url = get_theme_mod( 'penci_favicon' );
        return $favicon_url;
    }
    add_filter( 'get_site_icon_url', 'penci_filter_site_icon_url' );
}

At the end of functions.php file - like on this image.

In the next update version, we will add more this code also, so no worries the update will remove it.

Best Regards,

PenciDesign