kkarpieszuk

Since version 5.6 Advanced Custom Fields plugin hides WordPress native interface to display custom fields on the posts 
edit screen.
If you are plugin developer, advanced WordPress user or you feel much better when you have custom fields at 
a glance, you probably would like to discard this change.
When you activate this tiny plugin, you will see the native custom fields interface again.

Native Custom Fields Meta Box and ACF

Show WordPress native meta box for custom fields when Advanced Custom Fields plugin is active

Native Custom Fields Meta Box and ACF vs Ocean Extra