Hi,
You need to add the code below to the functions.php of your child theme.
remove_filter('sf_port_lightbox_svg_icon', 'uplift_lightbox_svg_icon');
remove_filter('sf_post_lightbox_svg_icon', 'uplift_lightbox_svg_icon');
remove_filter('sf_gallery_lightbox_svg_icon', 'uplift_lightbox_svg_icon');
remove_filter('sf_view_icon_svg', 'uplift_lightbox_svg_icon');
add_filter('sf_port_lightbox_svg_icon', 'uplift_post_svg_icon');
add_filter('sf_post_lightbox_svg_icon', 'uplift_post_svg_icon');
add_filter('sf_gallery_lightbox_svg_icon', 'uplift_post_svg_icon');
add_filter('sf_view_icon_svg', 'uplift_post_svg_icon');
Hope it helps.
-Rui