Toggling inventory options turns off product image and display tabs

I have an issue where a product is showing out of stock even though inventory settings are not enabled. I turned off the out of stock and low stock notices. Went back to the product page and the product images and tabs were missing. I had to re-tick them in the Product > display settings.

Still doesn’t sport out why it shows as out of stock here:

http://customsizebeds.co.uk/product/mattresses/premium-memory-foam-mattress-extreme/

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