Many of our blocks recently have changed and the editor in the "side" even though they are set to "content". We are using MB Builder with MB Blocks.
https://drive.google.com/file/d/1aYskAXO0mwdfdX3vJBK9iB01IG8paHqt/view?usp=sharing
'block_json' => [
'enable' => true,
'path' => '{{ theme.path }}/blocks',
],
'type' => 'block',
'context' => 'content',
'preview' => [
[
'on' => '',
],
],