Checklist tree for taxonomy

Hi Peter,

Where am I going wrong? 1. My checklist tree does not group into the parent. See image: https://jam.dev/c/e72f213f-db30-41bb-83b2-6dad1ef09b65

         [
                'name'          => __( 'Country focus', 'your-text-domain' ),
                'id'            => $prefix . 'academiccountry_focus',
                'type'          => 'taxonomy',
                'taxonomy'      => ['country-tags'],
                'placeholder'   => __( 'Type or select an option..', 'your-text-domain' ),
                'field_type'    => 'checkbox_tree',
                'flatten'     => true, //have also tried false
                'multiple'      => true,
                'parent' => 10151, 
                'query_args'    => [
                    'orderby' => 'menu_order',
                    'order'   => 'ASC',
                ],
                'admin_columns' => [
                    'position'   => 'after title',
                    'title'      => 'Country',
                    'sort'       => true,
                    'searchable' => true,
                    'filterable' => true,
                ],
                'columns'       => 12,
                'class' => 'rs_p5',
                'tab'           => 'page_5',
            ],

2. As a second question for when I get this working, how can I hide a level of the parent? I do not want "global" to be an option and want to start with region at second level