can't add items to cart unless signed in.

I am new to wordpress and am having an issue with the woo commerce shopping cart, it won’t add items unless you are first signed in. I have enabled guest checkout but it does not work. I have also contacted my host to see if it was a cacheing problem but that’s not it I de activated all plugins, changed themes and deleted and re-installed woocommerce but still nothing works. Has anyone else had this issue? Here is our site.
https://www.ivsha.org/test/