WooCommerce not changing cart total?

Question

WooCommerce

add_action( 'woocommerce_calculate_totals', 'woocommerce_calculate_total', 10, 1 ); 
    function woocommerce_calculate_total( $cart ) {
    if($cart->subtotal < 300){
        $cart->subtotal += 85;
        $cart->total += 85;
    }
}

The code works, but $cart->total always returns 0 and cannot be changed, so the Subtotal is larger than the Total.
WP-5.3.2. WC-3.8.1.

Answer 1

It was necessary to put a hook on woocommerce_after_calculate_totals instead of what I used.