Shop Image Size

Woo should automatically generate those thumbnails when you make and save any changes to the Thumbnail Width in Customizer > Woocommerce.

If thats not doing that, then try running the Regenerate Thumbnails plugin to create them.

If that don't work then make sure you're not using any plugins or functions that interfere with Woo images or the thumbnails

I wound up resizing all my images, one by one.

For Woocommerce that is the best way to go. Glad to hear you got a solution

Thanks