We recently increased the thumbnail image width from 300px to 600px to reduce blurriness on retina displays.
Most of our product images are 800px x 1000px but some older images are not the same. Hence we need to use a hard crop.
Once we made the change in customize-woocomerce-productimages, the images are not the same heights.
See attached images of our staging site and Live site
Are you able to help? This has always worked perfectly with your theme until we made this change