Hello,
I’m sorry to hear that you are facing issues with generating the sitemap for your website at https://domain.com/sitemap_index.xml_. It seems like you have already tried several troubleshooting steps, including clearing the cache, regenerating permalinks, and disabling caching for the sitemap in the theme.
Since you have exhausted the solutions provided in the FAQ, I recommend assigning this ticket to a human agent by clicking on the appropriate button so that they can further investigate the issue and provide you with a tailored solution.
Thank you for your understanding, and we will ensure that your concern is addressed promptly.
Have a great day!
Sources:
Rank Math Sitemap Issues and Their Fixes » Rank Math
Hello,
Thank you for your query and we are so sorry about the trouble this must have caused.
We might need to take a closer look at the settings. Please edit the first post on this ticket and include your WordPress & FTP logins in the designated Sensitive Data section.
Please do take a complete backup of your website before sharing the information with us.

It is completely secure and only our support staff has access to that section. If you want, you can use the below plugin to generate a temporary login URL to your website and share that with us instead:
https://wordpress.org/plugins/temporary-login-without-password/
You can use the above plugin in conjunction with the WP Security Audit Log to monitor what changes our staff might make on your website (if any):
https://wordpress.org/plugins/wp-security-audit-log/
We really look forward to helping you.
Hello,
I have updated the sensitive data as requested. Can you please check further?
Thank you.
Hello,
We have investigated the issue with your website and found that your sitemap is working fine when all your plugins except Rank Math are deactivated.

After re-activating the plugins, we found that the sitemap is still working, indicating a classic cache-related issue. Upon checking your w3 Total Cache settings, we noticed that you had not excluded your sitemap, which is likely the cause of the issue.
We have taken the step to add your sitemap to the exclusion list. Please let us know if you encounter this issue again.

Thank you for choosing Rank Math.
Hello,
I have updated the sensitive data as requested. Can you please check further?
Thank you.
Hello,
It seems that you repeated the previous message from the latest reply on this ticket.
As indicated before, the sitemap on the website is now loading properly so please delete the browser cookies and cache and try to access it again.
Don’t hesitate to get in touch if you have any other questions.
Yes, thank you, it was automatic response when I modified sensitive data.
Hello,
We are glad to know that this issue has been resolved. Thank you for letting us know.
This ticket will be closed now, but you can always open a new one if you have any other questions or concerns. We are here to help you with anything related to Rank Math.
We appreciate your patience and cooperation throughout this process.
Thank you for choosing Rank Math.