WordPress Draft Pages being indexed in Google

There is a difference between draft and noindex.

WordPress itself allows posts and pages to be saved as drafts. This is a feature that means that the pages/posts in question should not be publicly accessible (i.e. not accessible without a login). It would be highly unusual to find these on Google. Do you have a concrete example of what you can look at?

The specification noindex is again a property that can be set by SEO plugins on pages and posts. It recommends to the search engines how they should handle the pages/posts. It is only a recommendation, search engines do not have to adhere to it – but Google usually does. A concrete example would also be interesting here – or you can ask the support team of the SEO plugin you are using for the information.