Are you using Views/Blocks to create a custom template for single products?
It sounds like you are not, and if it is the case that the single products no longer show since updating Toolset WooCommerce Blocks while Views/Blocks are active then my first thought is that you perhaps have a Content Template assigned to products which is empty, so nothing is shown.
(The recent WC Blocks update changed how templates were assigned, having previously been a manual process in the settings, while now it is automatic, and it could be recognising that there is a content template for products and using it, even though it is blank.)
