Dated content appearing

[Adorno77]

I've recently had a problem with dated content appearing on a SERP listing.

So below my site that appears #1 for a branded search, most of my sitelinks have disappeared and when you go to 'latest from designweek.co.uk', the content (which is usually the most up-to-date) is sometimes 10+ years old although today it is showing one from yesterday plus ones from 2017 and 2015.

I don't have any other major problems in indexing and ranking. Google has indexed all the new material as normal.

I've done the following:

• Re-loaded the sitemap into sitemap, no problems.
• Rejigged the main nav so that elements that would push the crawler towards archive items are more hidden.
• Checked for obvious crawl problems. There was a spike of Indexed, though blocked by robots.txt last week that were pointing to a batch of archive pages that I put in robots.txt. I thought it was possible this may be related.
• Doing a site: search today doesn't throw up anything that would suggest why Google is prioritising older content although last week there were archive stories appearing on page 1 of the site: search.

Has anyone experienced anything similar, this prioritising of really old content?