In regards to website graders, reports, checkers, etc., we generally recommend examining these with a grain of salt, as it's a really tall order to build a tool that can successfully give accurate and meaningful feedback for every website on the internet.
Sometimes we see tools that are really great and maintained well, however, we see many other tools that give bad or inaccurate feedback based on the algorithms running the tool, e.g. it is poorly designed.
Additionally, these tools are typically used in trying to sell a service, so there's usually some bias involved as well.
If you have received website grader results or information from a website testing tool that you'd like our team to review, please create a new ticket and we'll be happy to provide our feedback and insight.