I've just created a new custom post type where I don't want to use the editor field. So I've disabled the Editor in the Supports tab. However, then it suddenly shows the Custom Fields in the backend although I didn't activate that option. So I tried a few different options and all don't behave as expected. With the editor enabled for example I don't see the custom fields or the author. As soon as I disable the editor, it does show those fields. I've made a short video illustrating the problem: https://share.getcloudapp.com/NQuJ2lG5
Thanks for the quick reply. I've disabled my current Kadence theme and disabled the plugin of WpVivid staging. The only plugins active are now of Metabox. And I'm running the latest WordPress install 5.7.
I did the test again, and although now it works better with the Editor option disabled. However, when I enable it, it still not works as expected. It still doesn't show some fields. See the recording: https://share.getcloudapp.com/geu46D6b
I'll check my other MB view issue and will get back to you on that too.
If you are using the Block Editor and want to show the Custom Fields box after enabling support Custom fields, please open the Preferences > Panel > Turn on Custom fields. Screenshot https://share.getcloudapp.com/v1uNdXk4.