Resolved
On existing sites where a Template Layout is assigned to display single products, after updating to Toolset WooCommerce Blocks 3.0 the Layout is no longer used and products are shown with whatever the theme normally outputs.
If you edit a single product post and try to set the Template Layout to be used, a message reports that “Your layout design will not yet show on WooCommerce products, because WooCommerce is using a template file that doesn’t display the layout”, but it is not possible to re-assign the Layout.
A fix for this is now available in updates to Layouts and the Toolset WooCommerce Blocks plugin.
If you don’t see an update notice on your plugins page, click the registered link for one of the Toolset plugins to take you to the custom Toolset installer page, and use the Check for Updates button, otherwise you can download the latest versions from your downloads page at toolset.com/account/downloads.