Hi Heinrich,
The HTML structure created from the WooCommerce shortcode is different, thus, making the code generated from the customizer settings inapplicable to it.
If you’d like to display these products in one Column, here is a CSS you may try adding to Appearance > Customize > Additional CSS:
@media (max-width: 768px) {
.gb-inside-container .woocommerce ul.products li.product {
width: 100%;
}
}
Hope this helps! Kindly let us know how it goes. 🙂