Your best bet is going to be official support. No one in the community is going to be able to diagnose whether or not you’re having a problem with your license, activating Pro, etc.
Make sure you’re at the top level Container using the indented hamburger menu. Then add an “HTML Anchor” under Advanced. In my screenshot below, it’s called “buy” without quotes. When you want to link to that Container, use the link “#buy” all by itself, also with no quotes.
Thanks for your responses. I finally found out that Yoast SEO is causing a conflict. Deactivating Yoast makes container links visible. Glad that I found it but now I hope that GB teams will have a look what is causing the problem.