Canonical points to a different host

What this means

The rel=canonical names a URL on another hostname, which hands the indexing rights for this page to a site you may not control. Cross-domain canonicals are legitimate for syndicated content, but they are far more often a template bug — a staging host, a CDN host, or a copy-pasted tag from another property.

How to fix it

If this page should be indexed on its own domain, point the canonical at its own absolute URL. Only keep a cross-domain canonical when the content is deliberately syndicated and the other host is the intended original.

Fix effort

This check needs review: the change can be drafted for you, but a person has to approve the wording or choose the target before it ships.

Authoritative source

https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls