Two sets of images upon activation

This means that your theme has hardcoded the display of images, where it should be using a WooCommerce hook. In some other cases, they’re using the hook but via some other method that has been missed by my plugin.

First port of call is to check in your theme folder, then  woocommerce/content-single-product.php

If you see the images in there, simply remove them, but leave the  woocommerce_before_single_product_summary action in place.

Also, make sure you’re not using YITH Image Zoom, as this will also add a set of images.