Confused with safari settings..advice needed

IPhone 7 latest software... Ever cookies,zombie cookies,persistent cookies I currently have six websites which can’t be cleared by any method from my website data when I enable block cookies and prevent cross-site tracking and use private browsing then search For one of the sites then close private private browsing should this clear all history and cookies??as this is not the case as when I go back to website data the list has increased and the data usage has increased,Am I right in thinking I’m not blocking cookies and I’m still being tracked despite having them turned on?????