Hello,
Thank you for contacting Rank Math, and sorry for any inconvenience caused.
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.

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.
Hello,
Thank you for that additional information, and sorry for the delay.
I’ve checked your site and replicated the issue then got this error:
api-fetch.min.js?ver=a783d1f442d2abefc7d6dbd156a44561:2
POST https://lujambio.nireweb.es/wp-json/rankmath/v1/updateMeta?_locale=user 404
Those errors usually are caused when something is blocking access to the WordPress REST API. If you are using a firewall, please disable that temporarily and see if the issue goes away.
Since you mentioned that you have already gone with checking for a plugin conflict, if the issue still persists, please contact your web host and ask if your server is blocking it, firewall policies, or even a security feature for the WordPress REST API getting disabled.
I hope that helps. Thank you, and looking forward to your update.
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.