In CartFlows version 1.10.0 we have introduced a new feature named Store Checkout. In this update, we have made significant changes to the global checkout which is now been deprecated and store checkout is added.
There are a few core changes in the store checkout, out of which, one is a deprecated change and that is the product tab is been removed from the store checkout flow.
If you would like to have that tab back again to display, you can use the below-mentioned filter to enable it.
add_filter( 'cartflows_show_store_checkout_product_tab', '__return_true' );
Note: Add the above filter to your child theme’s functions.php, here’s an article to help you Add Custom code.