Hello,
We apologize for the issue you are facing with your sitemap. The "Couldn’t fetch" error can occur for several reasons. Here are some steps you can take to troubleshoot and resolve the issue:
1. Validate Your Sitemap
Ensure your sitemap is correctly configured by using the Validate XML Sitemap tool. Enter your sitemap URL and click VALIDATE SITEMAP. If there are no issues, you should see a success message.

2. Ensure the Sitemap is Located in the Root Folder
Make sure your sitemap is located in the root folder of your WordPress installation. The URL should look like this:
https://yourdomainname.com/sitemap_index.xml
3. Check Indexing Settings
Ensure that your posts are set to index. Go to Rank Math SEO → Titles & Meta and enable the Index checkbox in the Robots Meta settings.

4. Flush the Cache
If your sitemap appears outdated, you may need to flush the sitemap cache. Navigate to Rank Math SEO → Sitemap Settings, increase the value of Links Per Sitemap by one, and save your settings.

Then, go to Settings → Permalinks and click Save Changes to ensure the current settings are applied.

5. Exclude the Sitemap From Caching
Make sure your sitemap is not being cached. You can refer to this knowledgebase article on ensuring that your sitemaps are excluded from caching.
6. Submit the Correct Sitemap URL
Finally, ensure you are submitting the correct sitemap URL in Google Search Console. It should be in the format:
https://yourdomain.com/?sitemap=1
If you have followed these steps and are still experiencing issues, please reply to this ticket, and a human agent from the Rank Math Support team will assist you further.
Thank you for raising this concern! We hope these steps help resolve your issue.
Sources:
Troubleshooting the “Couldn’t Fetch” Error in Google Search Console » Rank Math
This is an automated reply from Rank Math Support Bot. If you need further assistance, please reply to this topic and a human support agent will reply to you shortly.