Hello,
I’ve checked your sitemap, and it is returning a white page.
In this case, please follow the steps below for initial troubleshooting:
1. Flush the Sitemap cache by following this video screencast:
https://i.rankmath.com/pipRDp
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:
https://rankmath.com/kb/exclude-sitemaps-from-caching/
That should fix the issue.

Please let us know if that does not. We are here to assist.
The result of testing several times: when I turn off the following option it works fine. When I turn this option on again the original problem occurs again. Is it a bug of rankmath?
SITEMAP SETTINGS=>General=>Images in Sitemaps
My wordpress version: 6.1.1, Rank Math SEO version :1.0.111
For the new xml file, please refer to the existing address at:https://www.beadnova.com/post-sitemap1.xml
Hello,
We’re unable to replicate the issue on our test install with the Include Images in Sitemaps option using the latest version of the Rank Math plugin.
In this case, 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.
Thank you.
Hello,
I have updated the sensitive data as requested. Can you please check further?
Thank you.
Hello,
I enabled the Images in Sitemap and option and wasn’t able to replicate the issue. The nocache=1 parameter is not being added to the image URLs in the sitemap:

Please check again on your end and if the issue persists, please follow this guide to figure out which plugin is causing the issue as this must be due to a plugin conflict: https://rankmath.com/kb/check-plugin-conflicts/
Let us know how that goes. Looking forward to helping 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.