The reason are Security related rules only available on Developer Edition and above.
Some of the rules shipped in SonarQube can help you comply with PEP8 style guidelines, but this is probably not enough to say “you are 100% PEP8 compliant”, which is not the main focus of SonarQube analyser for Python.
However there are ways to integrate with other tools (e.g. Pylint) to enforce as much as possible a PEP8 compliant coding style: I would highly recommend you to read this other Community post (which talks on the case of SonarCloud, but most of it applies to SonarQube as well) and this one specific to SonarQube.