Pick www or not, and always serve https
Choose www or the root domain as your site's one address, 301 the other to it, and redirect http to https.
Your site answered on www and without it, over http and https. Search engines saw four copies of every page and split the credit between them.
The enemy is one site that search engines see as four.
Under Settings, SEO you can now pick the preferred host, www or the root domain, and send the other one there with a 301. A second setting redirects http visitors to https. Your sitemap, robots.txt, llms.txt and page canonicals always publish https URLs on the preferred host.
Try it: choose a preferred host, then open the other variant of your domain over http and watch it redirect.
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