Problem with Shopping Cart

[Troubletcat]

I've recently upgraded to v2.3.4 and I'm having some strange problems with the shopping cart.

 

When adding a product to the cart, the product doesn't seem to be added. In my case I had something in the shopping cart prior to the upgrade, and after hitting add to cart on a product and being redirected to the shopping cart page, I see this old product only. Attempting to remove this product or change the quantity has no effect.

 

However, if I then continue navigating, the shopping cart in the top bar will reflect the newly added item, and clicking the link there to go to the shopping cart, or going to the shopping cart directly, will also show the newly added item (and not the old item). Clicking "remove" on the newly added item takes me back to the phantom shopping cart containing that item added prior to the upgrade. If I then continue browsing again I can once again see the correct new shopping cart state.

 

When attempting to check out it checks out using the "phantom" shopping cart, not the actual current one.

 

Hopefully that explanation was clear, it's a very strange issue. Any ideas on how to fix it? Here's the website, you can see this behavior yourself (although your "phantom" cart will just be empty): https://guitarwoods.com.au/

 

Here's the relevant section of my /includes/configure.php (I noticed in similar issues this was often the problem, but I'm pretty sure mine is setup correctly? Correct me if I'm wrong):

  define('HTTP_SERVER', 'https://guitarwoods.com.au'); // eg, http://localhost - should not be empty for productive servers
  define('HTTPS_SERVER', 'https://www.guitarwoods.com.au'); // eg, https://localhost - should not be empty for productive servers
  define('ENABLE_SSL', 'true'); // secure webserver for checkout procedure?
  define('HTTP_COOKIE_DOMAIN', 'guitarwoods.com.au');
  define('HTTPS_COOKIE_DOMAIN', 'guitarwoods.com.au');
  define('HTTP_COOKIE_PATH', '/catalog/');
  define('HTTPS_COOKIE_PATH', '/catalog/');
  define('DIR_WS_HTTP_CATALOG', '/catalog/');
  define('DIR_WS_HTTPS_CATALOG', '/catalog/');

EDIT: Haha, wow. Looking at that again and noticing that the HTTPS_SERVER has the www. in the URL and the other doesn't...  Removing that seems to have fixed that issue.