Keywords not showing in the metabox and preview shows “null”

Hello,

In this case, assuming you are using the latest version of all the plugins and the themes (please update if not yet), it would seem like a conflict with one of the plugins or the theme you are using.

To determine that, please follow this troubleshooting guide:
https://rankmath.com/kb/check-plugin-conflicts/

Here is a video you can follow as well: https://www.youtube.com/watch?v=FcIWRhcUP2c

Only the site admin would know and your users won’t be affected by this troubleshooting.

If the issue persists, please edit the first post on this ticket and include your WordPress login 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/

Please do take a complete backup of your website before sharing the information with us.

We really look forward to helping you.

Hello,

Thank you for your patience.

I’ve replicated this issue on our test install and forwarded it to our development team for further investigation. We will get back to you shortly.

We would really appreciate your kind patience regarding this matter.

Meanwhile, please don’t hesitate to contact us anytime to assist you further with anything else.

Looking forward to helping you.

Thank you.