Issue with Post Sitemap Splitting, Duplicate URLs, and XML Error

Hello,

We apologize for the issue you are facing with your blog post sitemap. Thank you for providing detailed information about the problem.

Regarding your concerns:

1. Fitting All URLs into a Single Post Sitemap: The standard practice for sitemaps is to limit the number of URLs to 50,000 per sitemap file, but it’s generally recommended to keep it lower (like 200) to avoid server load issues. Unfortunately, Rank Math does not support combining all URLs into a single sitemap if it exceeds the limit. Therefore, you will need to maintain multiple sitemaps as you currently have.

2. Duplicate URLs Across Multiple Post Sitemaps: Having duplicate URLs across multiple sitemaps should not cause significant crawling or indexing issues, as search engines are designed to handle such scenarios. However, it is best practice to avoid duplicates to ensure that search engines can efficiently crawl your site without confusion.

3. Recommended Way to Resolve This: To ensure proper sitemap structure without duplicate entries, consider the following steps:

   • Check for Exclusions: Ensure that you are not unintentionally excluding any posts from appearing in the sitemap settings. You can do this by going to Rank Math SEO → Sitemap Settings and checking the options for each post type.
   • Review Custom Canonicals: If you have set custom canonical URLs for any posts, they may not appear in the sitemap. Ensure that all posts have the correct canonical settings.
   • Flush Permalinks: Sometimes, flushing permalinks can help resolve issues with sitemap generation. You can do this by navigating to Settings → Permalinks in your WordPress admin area and clicking “Save Changes.”
   • Check for Plugin Conflicts: Use the Health Check plugin to identify any potential conflicts with other plugins that might be affecting your sitemap.

If you continue to experience issues or if there are specific URLs that are duplicating, please reply to this ticket with your site URL so we can assist you further.

Thank you for raising this concern, and we hope this helps resolve your sitemap issues!

Sources:
Rank Math Sitemap Issues and Their Fixes » Rank Math

Hello,

Sitemaps are only one of the few methods Google uses to discover your URLs, so it is fine for your articles to be referred to other URLs on your sitemap.

However, your posts should not be duplicated in another sitemap. Please exclude the Sitemap files of the Rank Math plugin in your caching plugin. The cache could be via a plugin or from the server. For plugins or Cloudflare, please follow this article:
https://rankmath.com/kb/exclude-sitemaps-from-caching/

If the issue persists, disable the transient cache for the sitemap by applying this filter. This will make sure that your XML sitemap always reflects the latest changes on your site:

/** 
 * Filter if XML sitemap transient cache is enabled.
 *
 * @param boolean $unsigned Enable cache or not, defaults to true
 */
add_filter( 'rank_math/sitemap/enable_caching', '__return_false');

If you’re not sure how to add this code, you can follow this guide:
https://rankmath.com/kb/wordpress-hooks-actions-filters/

Looking forward to helping you.