My rank math sitemap_index.xml is not updating.

Hello,

We apologize for the issue you are facing with your Rank Math sitemap not updating. Since you are using an NGINX server, there are a few steps you can take to troubleshoot this issue further:

1. Check NGINX Rewrite Rules: Ensure that the necessary rewrite rules are added to your NGINX configuration file. You can add the following code:

   # START Nginx Rewrites for Rank Math Sitemaps
   rewrite ^/sitemap_index.xml$ /index.php?sitemap=1 last;
   rewrite ^/([^/]+?)-sitemap([0-9]+)?.xml$ /index.php?sitemap=$1&sitemap_n=$2 last;
   rewrite ^/([a-z]+)?-sitemap.xsl$ /index.php?xsl=$1 last;
   # END Nginx Rewrites for Rank Math Sitemaps

2. Flush Sitemap Settings: After adding the rewrite rules, go to Rank Math SEO → Sitemap Settings in your WordPress admin area and make any minor changes to the Links Per Sitemap count, then click the Save Changes button.
   

3. Flush Permalinks: Navigate to WordPress Dashboard → Settings → Permalinks and click the Save Changes button without making any changes. This can help refresh the permalink structure.
   

4. Exclude Sitemap from Caching: Ensure that your sitemap is excluded from caching. You can refer to this dedicated knowledgebase article for guidance on how to do this.

5. Disable Transient Caching: If the above solutions don’t work, you can add the following filter to your theme’s rank-math.php file to disable transient caching of your sitemap:

   add_filter( 'rank_math/sitemap/enable_caching', '__return_false');

If you have followed all these steps and are still experiencing issues, please reply to this ticket, and a human agent from the Rank Math Support team will assist you further. Thank you for raising this concern!

Sources:
Rank Math XML Sitemaps on NGINX Servers » Rank Math