As was mentioned, “Additional Information” tab will only show if the product has weight, dimensions or attributes (with “Visible on the product page” checked). Custom tab1, Custom tab2, single product custom tab are empty by default, so there is no content to display. Add titles and content for custom tabs and you will see them.
As I can see, Single Product builder is disabled on your site. Have you published changes? Have you cleared CDN cache?
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.