A “New reasons prevent pages in a sitemap from being indexed” email from Google typically indicates that the search engine has encountered issues that are preventing certain pages in your sitemap from being indexed.
This notification is part of Google’s efforts to help webmasters understand and resolve indexing issues, thereby improving the visibility and performance of their websites in search results.
Find out more in our blog post, Understanding Google’s “New Reasons Prevent Pages in a Sitemap from Being Indexed” Email