Product catalog image sizes

The image size setting sets the size of the image which is sent to the browser, not the size at which it is to be displayed.

The size at which it is displayed is set by the style sheets for your theme. Sometimes this size can be changed with custom css. Depends what you would like to do.

If you want them to show bigger, you could try reducing the number of products per row at:
Dashboard > Appearance > Customize > WooCommerce > Product Catalog > Products per row

I don’t want them bigger, but all the same size. Since the images uploaded are identical in size, I’m puzzled ;(

You could go with forcing a standard height with:

.woocommerce ul.products li.product a img {
  height: 150px !important;
}

Some images may be a little squashed, some stretched.

>Some images may be a little squashed, some stretched.

But why would it treat them differently? I shouldn’t need to adjust css to do this ;(

never mind, I deleted the images, reuploaded and all is fine. What a waste of time but thanks!