I’m having the same issue. Following.
Hello,
Thank you for contacting the support and sorry for any inconvenience that might have been caused due to that.
Could you please confirm you are on the latest version of the Rank Math? The latest version is v1.0.69.1
Please clear the website cache and Rank Math Transients by going to Rank Math > Status & Tools > Database Tools > Remove transients

@ Noelle Tabor you can also perform the above steps.
Let us know if the issue persists.
We are here to assist you.
I’m on the latest version v1.0.69.1 and I did what you say and nothing is changed!
Hello,
All the SEO data including the one you add in the Popup is saved when you Update the Post. So after adding the SEO Title & Description in the popup, just close the popup and update the Post. Please check this screencast: https://i.rankmath.com/1yP02s
I hope that helps.
Hi,
This work only for new posts, But for old posts not work.
When I edit old posts to add meta description then closed the popup then click update, nothing changed.
Check the screen video shared in sensitive date
Hello,
Can you please add your site’s admin access in the Sensitive Data Section?
Looking forward to helping you.
Hello,
I have updated the sensitive data as requested. Can you please check further?
Thank you.
Still an issue for me too. I’ve opened a support ticket and will respond there.
Hello,
I see the issue on your site and it seems to happen only on the Firefox browser. I made some changes in the plugin’s classic.js file and that seemed to have fixed the issue. Can you please confirm?
Please do clear the browser cache before checking.
I hope that helps.
Yes its fine now and working. Thanks
Hello,
We are super happy that this resolved your issue. If you have any other questions in the future, know that we are here to help you.
If you don’t mind me asking, could you please leave us a review (if you haven’t already) on https://wordpress.org/support/plugin/seo-by-rank-math/reviews/#new-post about your overall experience with Rank Math? We appreciate your time and patience.
If you do have another question in the future, please feel free to create a new forum topic, and it will be our pleasure to assist you again.
Thank you.