If both www.yoursite.com and yoursite.com load as separate, live sites instead of one redirecting to the other, search engines see duplicate content at two different URLs and split your ranking signals between them instead of concentrating everything on one canonical domain.
If both www.yoursite.com and yoursite.com load as live, independent sites instead of one redirecting to the other, search engines see duplicate content and split your ranking signals between two URLs instead of concentrating them on one.
The non-canonical www/non-www variant correctly 301-redirects to your single canonical domain.
Fix it, then re-scan — the check confirms itself. No manual checkbox, the scan is the truth.
Run this check in H.I.V.E. →