Hello,
1) Update WooCommerce plugin to 4.0.1 version because 4.0 version has bugs with the product editing.
2) Why do you need this plugin? Why don’t you want to use a built-in option for the gallery images https://gyazo.com/1b9ee850897fe22e3036209685ac5733 + http://prntscr.com/rq4ma2 and built-in variation swatches? Third-party plugins may conflict with the custom slider that we use for the single product gallery and require additional customization of these plugins.
Regards