This issue is due to a change in the functionality of WooCommerce in combination with a custom theme. Up to now, the template file cart.php used both do_action('woocommerce_cart_collaterals'); and woocommerce_cart_totals(); to show the cart totals. In the current version, the second method should not be used anymore in this context. After removing the second method call in the theme override of THEMENAME/woocommerce/cart/cart.php, the totals appear once again.