Core Sitemap or Plugin Sitemap
Compare the Sitemap entry with Recycle Bin, Publish Status, and Current Permalink of the post. An outdated plugin sitemap can last longer than the data set.
Using robots.txt and the delivered XML file, determine the active sitemap producer. WordPress Core and SEO plugins can select different content and taxonomies. Exclusions belong in this source and not in a downloaded XML copy.
Where to check the setting in WordPress
Go to /wp-sitemap.xml if the core sitemap is used. With an SEO plugin, you determine its sitemap index via robots.txt instead. Check whether the affected content is published and contained in the selected content type or taxonomy.
Example of this specific finding
Illustrative control case: The sitemap calls /product/expiration model/, this URL provides 404. The product was either deliberately removed or disappeared due to a routing error.
follow-up audit in WordPress
Review a published paper, a draft and a relevant taxonomy. After a change, retrieve the sitemap index and the affected partial sitemap without logged in session.
Upon final removal, take the record from the sitemap selection. In the event of unintentional unreachability, restore the URL or set a suitable final destination.
Derogations and scope
A deleted page may correctly deliver 404. The contradictory inclusion in the sitemap is the part to be checked here.
Related: WordPress with classic or block theme. SEO plugins and page builders are different; there is no universal menu path for all installations.
Classify the general error
Definition, system-independent causes and further correction examples: Differentiate deleted and accidentally missing pages