Hello,
Thank you for contacting us and sorry for any inconvenience that might have been caused due to that.
In this case, we suggest you while saving the metadata, please keep the browser console open in the “Network” tab and see what is the status code of the following route: https://www.yourdomain.com/wp-json/rankmath/v1/updateMeta?_locale=user
You can find the browser console in your browser following this guide: https://balsamiq.com/support/faqs/browserconsole/
If it’s returning any other value than a 200, there’s something wrong with the route and we would request you to get in touch with your hosting provider to make sure that REST APIs are not getting blocked.
However, if it returns 200 but still not saving then, 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/
Looking forward to helping you.
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.