I have the same problem. After reviewing the plugin code I found that the cart shortcode handler definitely won’t show anything if the cart is empty (this is from version Version 4.1.7):
function show_wp_shopping_cart_handler($atts) {
$output = "";
if (cart_not_empty()) {
$output = print_wp_shopping_cart($atts);
}
return $output;
}
I ended up adding an “else” clause to that handler just to make sure the shortcode is being called (and it is).
This seems to be a weak point in this handler. Shouldn’t it show something regardless?