Featured image attachment issues

When you add an image through “Add Media”, the Easy Fancybox works since the image is linked as an image attachment, but the product image for CartPress is the “featured image”.

For some weird reason, the featured image in CartPress stopped acting as a linked image attachment and became a “static” image. How can I edit the template php or css to make the featured image back to how it was before, linkable, so the Easy Fancybox can function since the lightbox only works for linked images.