Cart not assigned to customer during checkout

-- url of the page with the problem -- : localhost
-- HikaShop version -- : 2.3.3
-- Joomla version -- : 3.6.6
-- Error-message(debug-mod must be tuned on) -- : See below

In a site I am developing I add an item to the cart and proceed to checkout. I then enter the registration details for a new customer and go to the next page. It asks if the delivery address is same as billing address and I click Next.
Now it goes straight to the screen which the user gets if they login (i.e edit account info, manage addresses, etc.) instead of continuing with the checkout process.
When I look at the admin area the customer record has been created and there is a cart entry but it says "No registration" in Username column. So it looks looks like the cart is not being assigned to the customer so the checkout process is being abandoned. This problem seems to have occurred since updating to 2.3.3

I set error reporting and only error is on page which asks about billing/shipping address: get unresponsive script in media/jui/js/jquery.js:346. Don't know if this is related.