Two emails from Search Console arrived the same morning. The first was the one that worried me:
New reasons prevent pages in a sitemap from being indexed on site utilorax.com
Excluded by 'noindex' tag
Read that carefully. Pages in a sitemap — pages I am explicitly asking Google to index — are being skipped because they carry a noindex. That is a contradiction, and it is the kind that quietly costs you: the sitemap says "index this", the page says "don't", and Google believes the page.
Fifty-one of them. My site has around 6,000 URLs across five languages, so 51 was small enough to be a real bug and large enough to matter.
