SonarQube LTS 7.9 DEVELOPER edition does NOT contain C/C++ Plugin?

Yes we followed the documentation, we run SonarQube in Docker. The Sonar Developer edition docker image is taken from Sonar private repository. We have new Sonar service (Version 7.9.1.27448) up and running without any problems for a few weeks already with most of the plugins you have in your Market place. And just now we got a request from one of our team who was using this C/C++ plugin. Our System says we run Developer editions, see a screenshot

attached. and the system health is ok.

I also noticed we have similar problems with other plugins which we do not currently use, but shall be able to use as part of Developer edition, like ABAP, Swift, PL/SQL.

Please advise on how to troubleshoot this problem.