Page keeps refreshing / cart empties

-- url of the page with the problem -- : www.phoenixmediademos.com
-- HikaShop version -- : 3.5.1 essential
-- Joomla version -- : 3.8.2
-- PHP version -- : 5.6.35

I'm uploading a new website to www.recoverycbd.ie . The old site is using hikashop with no issue but I am having a problem with the new website. When I add the product and go to the checkout page I can't continue with the order. When I click login I get re-directed back to the homepage and the cart automatically empties. I get the message the cart is empty. If I click next as a guest the page just refreshes to checkout step 1. As far as I can see I have hikashop configured pretty much the same as the old site and we are using the same payment plugin. It may be an issue with the template I'm not really sure.

The other issue I'm having is I can't seem to get the shipping method to display. I have it set to published and I'm pretty sure I have set correctly in the checkout workflow.

I have the site uploaded to a test server so you can have a look at it I can't upload it to its normal domain until I fix the bug. www.phoenixmediademos.com

When I set error reporting to maximum and debug system to yes I get the error

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 11391273 bytes) in /home/phoenixmediademo/public_html/plugins/system/debug/debug.php on line 347

Thanks

A quick edit.
I set checkout legacy to no and I can now complete the order. The only problem now is the images on the checkout page in the order summary are now way to big. Can I change the image size for just the checkout in configuration ?

I still can't get shipping to publish though. Can I PM someone login details?

Thanks