I’m sorry you are experiencing a blank meta box. A blank meta box issue occurs due to a JavaScript conflict. We’d like you to perform a conflict check to help us determine the next steps while saving you time.
Often, we see problems occur in combination with another plugin or theme. The fastest way to rule out any conflict is to deactivate all non-Yoast plugins and switch to a standard theme like Twenty Twenty-Two.
Please test this on your development or staging site if you have one. If not, we recommend using the Health Check & Troubleshooting plugin. This plugin has a troubleshooting mode, which does not affect normal visitors to your site.
If you’re unfamiliar with checking for conflicts, we’d like to point you to a step-by-step guide that will walk you through the process: How to check for plugin conflicts
If you feel uncomfortable doing this yourself or if this does not solve your issue, our Yoast SEO Premium plugin comes with one year of (technical) support.
I’m sorry that the issue persists. Do you mean that the meta box is blank when you switch to a default WOrdPress theme and only have the Yoast SEO plugin active? If yes, while you’re on the screen, can you please check if there are Javascript errors on your browser’s console? You may follow the steps here – https://yoast.com/help/how-to-find-javascript-errors-with-your-browsers-console/
