Hello, @KD,
You may try to disable global option of stretching product images -> Theme Options -> WooCommerce -> Shop -> Products Style -> https://prnt.sc/sMXZVvMN5P7l
Also, about the size of product images read here – https://xstore.helpscoutdocs.com/article/89-product-images
https://woocommerce.com/document/fixing-blurry-product-images/
It is recommended to use a graphics editor and prepare product images (make them the same size) before uploading images to your media gallery.
Regards 8Themes Team.