Add to cart button on detail page falsely shows record deleted

The current product results page uses the WA magnifying glass as a link to the detail page. There are also other areas of the site where you can link to the detail page without going through search/results. All seem to work fine.

I've added an Add to Cart button to the detail page so users can add the product to the cart without searching, which used to work as well.

When the Add to Cart button is clicked now, the page shows 'record has been deleted' and the product detail information is gone (only the cart buttons are there). Also, when I return to the cart, the products are still there and nothing has been deleted.

I've adjusted the layout recently and may have moved some things around vital to the eCart.