Hello,
Thank you for contacting Rank Math and bringing your concern to our attention. I’m sorry for the delay and for any inconvenience this issue may have caused you.
I checked all your listed sitemaps, and they are all working fine.
1. Please delete the sitemaps from the Google Search Console.
2. Clear your website cache and add sitemap_index.xml and *-sitemap.xml to the exclusion list in your Cache plugin. https://rankmath.com/kb/exclude-sitemaps-from-caching/
3. Add thesitemap_index.xmlfile again to your Google Search Console.
I hope that helps, and please do not hesitate to let us know if you need our assistance with anything else.
How to clear my website cache by clearing wprocket cache
Hello,
You can clear the WP Rocket cache by following these methods:
Go to the Settings → WP Rocket → Dashboard tab and press the Clear cache button.
Another way is via the WordPress toolbar (or admin bar). Roll over the WP Rocket menu link, and you will see a dropdown menu. Click on the Clear cache link.

We hope that helps. Please don’t hesitate to contact us again if you need further assistance.
did all the steps still the same error
Hello,
When we checked the sitemap it shows as loading fine from our end:

Please clear your browser cookies and cache and try to access it again to make sure it’s not being cached by your browser.
Don’t hesitate to get in touch if you have any other questions.
https://imgur.com/a/mZCyRer
even none of my URL is getting indexed
still not able to do that
Hello,
I tested the sitemaps using this tool and the sitemaps are not getting cached now.

I also accessed the sitemap as Googlebot and there are no issues found:

The robots.txt file also seems fine.
In this case, as you’ve resubmitted the sitemaps, please wait for Google to re-crawl the website and see if the issue gets fixed.
Hope this helps.
Thank you.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.