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A client's developer moved a site onto a new (WordPress) CMS, where the only change was URLs - the front end code stayed the same. The site is 10+ years old and previously had fantastic rankings (#1-4) with inner pages for some relatively generic search phrases (eg 10,000 searches / month in the UK, per Keyword Planner). Now, on Desktop searches the site isn't appearing anywhere in the 300+ results for a key search phrase, where it used to rank between #2-4; however over the last 3 weeks on Mobile the site ranks better than before, even though the site isn't at all mobile-friendly (it's over 10 years old). During the move, there were some errors by their developer: mistakenly left in a sitewide rel=canonical tag referring to the homepage 3-4 301s before finally reaching new URLs a lot of 301s missed (250+ crawl errors appeared in Search Console) page content differentiation by parameter, instead of individual URLs For example, the page that used to rank for the targeted phrase, this left 4 different URLs indexed, with the same content. To tackle this, we have so far: put in correct rel=canonical tags set up Search Console to recognise URL parameter as differentiating content fixed all crawl errors appearing in Search Console added a link direct to the problem page, direct from the homepage stopped duplicate content being indexed (including for the page in question) ensured the page load speed is still good (< 0.75s) Ranking for Desktop over Mobile would make sense, but not Mobile over Desktop!  I'd really appreciate any advice on how to tackle this. Thanks!