For those looking for the solution:
1. The product details recordset was in the code shortly before the "Add to Cart" form and button that displays with each individual item on the page (within a repeat region.)
2. The 'add to cart behaviour' was near the top of the page, just below the regular page recordsets.
3. The add to cart behaviour needed the information about the products that was within the repeat region - BELOW/AFTER the add to cart behaviour code.
4. Situation was resolved by creating a duplicate recordset at the top of the page BEFORE the add to cart behaviour which contained the informatino for all available items, allowing the add to cart behaviour to reference the item properties.
I hope this helps others.