An address of your domain does not end up on your main address, or only after more than two redirects.
If both the name with www and without www show the site, Google sees two sites with the same text. Every extra redirect also costs loading time and passes on less value.
Snaglist compares where each address ends up with where your site's own address ends up. Over two redirects counts as a detour. Over http no answer is listed here too, because browsers try https first.
Snaglist reports this as a warning. It costs 15 percent of the page in the health score. Fix it before your next crawl.
In the report for your client this appears under the heading "Addresses that do not redirect cleanly". When everything is in order, the report says: "Every address goes straight to your main address".
Snaglist checks every page of your site, for this issue and all the others. Start for free, no credit card needed.
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