Missing Reviews tab

We are currently developing a theme from scratch for a clients WooCommerce store. We are testing out the shop pages without overriding the default WooCommerce templates and we aren’t currently able to see the “Reviews” tab, even when we create a review. If we switch to our of WordPress’ default themes, the tab appears, but no matter what we try, we cannot seem to make it appear when our theme is activated. Any help much appreciated. Many thanks