Ticket #45257: 45257.2.patch

src/wp-admin/includes/meta-boxes.php

@@ -1360 +1360 @@
         if ( post_type_supports($post_type, 'trackbacks') )
                 add_meta_box('trackbacksdiv', __('Send Trackbacks'), 'post_trackback_meta_box', null, 'normal', 'core', array( '__back_compat_meta_box' => true ) );
 
-        if ( post_type_supports($post_type, 'custom-fields') )
+        if ( post_type_supports($post_type, 'custom-fields') ) {
                 $screen = get_current_screen();
                 if ( ! $screen || ! $screen->is_block_editor() || (bool) get_user_meta( get_current_user_id(), 'enable_custom_fields', true ) ) {
                         add_meta_box('postcustom', __('Custom Fields'), 'post_custom_meta_box', null, 'normal', 'core', array( '__back_compat_meta_box' => false, '__block_editor_compatible_meta_box' => true ) );
                 }
+        }
 
         /**
          * Fires in the middle of built-in meta box registration.