If you’ve recently added this theme, you may need to regenerate your thumbnails as each theme has different sized images.
If you go to wp-admin > woocommerce > settings > products > display
You’ll see a section for Product Images. If you click the link ‘regenerate thumbnails’ it takes you to the plug in which you run to crop your images to the correct size. I’ve been running mine all day as have over 11,000 that needed to be resized. But I’m hoping it’ll be worth it and all images will appear the same size (unless of course the vendor has uploaded tiny images that are small than the size that they are being cropped to.
This is the plugin you will need. I’ll be removing it once I’ve regenerated all my images and hoping new ones added will be the right size: https://wordpress.org/plugins/regenerate-thumbnails/
Good luck
(apologies to JanStudio if I’ve answered incorrectly, just trying to help)