woocommerce_add_to_cart_redirect porblem

Hi guys!

If users add a product to their cart, then navigate to a different page, and then try to re-add a subscription product to their cart, the user is redirected to the home page.

I use this code in the functions.php :
<?php
add_filter (‘woocommerce_add_to_cart_redirect’, ‘woo_redirect_to_checkout’);
function woo_redirect_to_checkout() {
$checkout_url = WC()->cart->get_checkout_url();
return $checkout_url;
}

I use this link in my button:
http://my-site.com/?add-to-cart=productID

my site: http://d8c.ebd.myftpupload.com/60daychallenge/
To ad to cart, click the first button: ‘krijg direct toegang’
To clear the product out of your basket, go to: http://d8c.ebd.myftpupload.com/winkelwagen

How can I fix this?

Thanks in advance for your help!

Gr. Chris

https://wordpress.org/plugins/woocommerce/