Some pages never recover after a migration because a signal that held their ranking was not carried over to the new page, and the loss usually traces to a specific, findable cause rather than bad luck. When a page that ranked well before a move fails to come back, the most common explanation is that something that fed its ranking, the redirect, the content, the internal links, or the underlying strength, broke or was dropped in the transition. The migration did not randomly pick that page to lose; it failed to bring something forward. This is observed behavior in migration recoveries, so confirm it by tracing the specific page rather than assuming the outcome was arbitrary.
The redirect causes are the first to check. A broken redirect that returns an error, a missing redirect that leaves the old URL stranded, or a redirect pointing at the wrong target page all sever the link between the old URL’s accumulated signals and the new address. When the redirect does not cleanly map old to true equivalent, the signals it was supposed to carry never arrive, and the new page starts closer to scratch than to where the old one stood.
Other causes sit in the content and structure. If the new page changed enough that its content or intent no longer matches what ranked, the relevance that earned the position is gone. If the page lost internal links or its place in the site’s hierarchy during the rebuild, it lost the internal support that helped it rank. And sometimes the migration simply exposes a page that was already weak, where the move removed a marginal advantage and revealed that the ranking was fragile to begin with. The redirect cases are usually recoverable; the weak-page case may not be.
To respond, audit the non-recovering pages one by one across redirect, content, and links. Confirm the redirect resolves cleanly to the right target, compare the new content and intent against the version that ranked, and check that the page kept its internal links and structural place. Fix the carried-over signals that broke, and for pages that were weak before the move, decide whether to genuinely strengthen them or let them go. Trace the lost signal rather than blaming the migration.