Maybe someone can help me, suddenly is not showing the form field into any post. When I go to edit my custom fields, the section where you choose the rules doesn’t appear. After publish, and refresh the page, then appears, but even I select, is not updating my option and after refresh the page (because in theory is saving the option), again the section disappears, and I don’t know how to fix that.
Also, I removed all the plugins to check if was something about related with this…but neither fix the problem.
This could be stemming from server configuration settings.
It is recommended to run at least PHP 7.2 for WordPress 5.x.x to run smoothly and you may have to update if your server is running an older version.