Hello,
Thank you for contacting Rank Math and bringing your concern to our attention. I’m sorry for any inconvenience this issue may have caused you.
In this case, locate the .htaccess file and replace it with the default WordPress .htaccess file. You can get the file contents here: https://wordpress.org/support/article/htaccess/
Please take a backup first of your current .htaccess file before making any changes. You can also get in touch with your web host for assistance.
Once done, clear your website, browser, and server’s cache (if any) and see if the issue is fixed.
If the issue still persists, 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.
Hi
Thank you for your reply. So far we have tried the following:
1. We don’t have .htaccess as the server is running Nginx
2. Disabled all plugins except RankMath
3. Switched to theme default WP theme
4. Checked that access to /wp-json/rankmath/v1/updateMeta isn’t being blocked by a firewall. The host company have confirmed these
The host company have conducted investigations and believe the issue is down to Nginx
Please could you advise if their are any Nginx config changes that need to be made in order for RankMath to operate correctly.
To clarify, the only problem I am seeing is when updating the RankMath data on pages and posts. For example, if I add a Focus Keyword it updates the score, but when I click Update the keyword isn’t saved.
When clicking Update I see this in Dev Tools:

Summary
- It’s not a firewall issue
- It’s not a plugin issue
- It’s not a theme issue
- It’s not .htaccess, as we are on Nginx
Therefore I suspect it is an Nginx config issue. Please can you advise?
Hello,
The screenshot you shared doesn’t seem to load, it returns a 404 error.
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.
Hi
Thank you for your reply. I have sent you the details you need. Good luck, and thanks!
David
Hello,
This is happening because of the rule to add a trailing slash to the website URLs and it’s applying also to the REST API routes.
This is not an issue with our plugin but rather the server configuration, so we recommend checking that with your hosting provider and either removing the rule we mentioned or making sure that it doesn’t apply to REST API routes from WordPress or any other plugin.
Don’t hesitate to get in touch if you have any other questions.
Thank you. This worked perfectly
Hello,
We are super happy that this resolved your issue.
If you have any questions in the future, please feel free to create a new forum topic, and it will be our pleasure to assist you again.
Thank you.