Cannot add subscription product to cart

I have a product with the option to subscribe as a membership
When adding to cart, it makes you create an account and after verification I end up back on the product page. When trying to add to cart I get the error “Something went wrong when adding this item to the cart.”

I have tested after making and verifying an account.

This is the link to my product
Something went wrong when adding this item to the cart.

Here is my site Read-Only:

I too saw this same error message recently when submitting a subscription. I found that my test user account was not logged in. I had not yet implemented Login/Logout and once I did, I was then able to log in and re-test the subscription ‘Buy Now’ with success.