Hello @nimonogi,
Thank you for contacting us, and sorry for any inconvenience that might have been caused due to that.
Can you please try following the steps below to see if that works for you?
#1. Flush the Sitemap cache by following this video screencast:
#2. 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:
#3. If the above steps doesn’t seem to work, kindly apply the following filter code to your site.add_filter( 'rank_math/sitemap/enable_caching', '__return_false');
Here’s how you can add a filter/hook to your WordPress site:
If the issue persists, please share your HTML sitemap URL so that we can check as well.
Let us know how it goes. Looking forward to helping you.