Hello,
Thank you for contacting Rank Math and sorry for any inconvenience that might have been caused due to that.
We might need to take a closer look at the settings. Please edit the first post on this ticket and include your WP logins in the designated Sensitive Data section.

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.
Hi,
I tried multiple times but can’t see the issue.
The next time this issue results, please share the contents of you .htaccess file and ping us so we take a closer look.
We look forward to helping you.
Hi, after (i think) arround 4 days the sitemap creates a 404 error (again)
The page is hosted at a nginx server, so no htaccess file.
What can we do, since this is a very strange behavior..
once again, when refresh the wp permalinks, everything is fine again.
Hi,
Please go to WordPress Dashboard > Rank Math > Sitemap Settings.
For Nginx specific servers, we have provided instructions there to get rid of the issue like the one you are facing.
This is already added by our hoster. so i dont think that it has something to do with the hoster/server
Hello,
Thanks for the reply.
I have just performed a CURL request for your sitemap file here https://onlinecurl.com/ and it looks like it is still getting cached.
Could you please check if your host is still caching this file?
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.