It is not a bug, you will have the same situation with any theme you are using, it is how WooCommerce works, it takes the Featured image into the gallery as the first one. Here is an example from our demo – https://xstore.8theme.com/product/bae-top/
You can contact the support of WooCommerce to get a detailed explanation and maybe advice on how to change it.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.