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Hi! Have you no indexed the pages too? That may help to make sure that they aren't being crawled if that's concerning you. May at least give Google another signal not to crawl those pages. Obviously it's not a catch all as there's only so much you can do to tell Google not to crawl a page. Sometimes if the alternative page is linked to internally (which it sounds like it is), then it will automatically crawl it even though you've said it has a canonical on it as you're showing that the page is important to your site. May be worth testing a few pages to see if it has an impact.