Hello,
Thank you for contacting Rank Math and sorry for any inconvenience that might have been caused due to that.
Please make sure to exclude all your sitemap URLs from being cached on your site then do the following:
1. Head over to WordPress Dashboard > Settings > Permalinks
Hit the save button once.
2. Go to WordPress Dashboard > Rank Math > Sitemap Settings
Hit the save button once.
3. Head back to your GSC and resubmit your sitemap. Submit only the main sitemap URL(sitemap_index.xml) and remove any other submitted sitemap URLs.
That should resolve the issue.
If it doesn’t, please do let us know so we can look at this further.
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.