For as long as I can remember, Google's John Mueller has been preaching consistency when it comes to SEO. He did it again last week on Twitter saying that often issues arrive when you provide Google with conflicting signals around canonicals, internal links, sitemaps, hreflang, rel-canonical, etc. So be consistent across all your signals.
If you have 301 redirects in place to one URL but the canonical says something else, that is confusing. If you are using hreflang but canonicals conflict with them, that can be an issue. The lists goes on and on.
Be consistent, it is not just a life lesson but a technical SEO lesson.
John wrote:
The clearer you make your signals, the easier they are to trust :). For example, if internal links, sitemaps, hreflang, rel-canonical, etc all align, there's not much to guess. Often it's quite inconsistent & harder to pick.
The clearer you make your signals, the easier they are to trust :). For example, if internal links, sitemaps, hreflang, rel-canonical, etc all align, there's not much to guess. Often it's quite inconsistent & harder to pick.
— John ☆.o(≧▽≦)o.☆ (@JohnMu) February 28, 2018
Forum discussion at Twitter.