Product added to cart with required options

I’m testing the lite version of WooCommerce Extra Product Options by adding several required options to a single set. When no fields are completed and the “Add to cart” button is clicked, I receive a warning stating the fields are required. Which is what I’d expect to see happen. If I complete only one of the required fields and click “Add to cart”, I still receive the warning; however, the product is added to the cart.

It seems like the product should only be added to the cart if all required fields have been completed. I’ve tried using different themes and deactivating plugins, but it behaves the same. Is this a bug with the lite version?