不显示灵活内容的中继器字段中的ACF选择字段

acf_add_local_field_group(array(
    'key' => 'group_60d5e9c7f3b35',
    'title' => '灵活内容示例',
    'fields' => array(
        array(
            'key' => 'field_60d5ea0b8b235',
            'label' => '选择布局',
            'name' => 'layout',
            'type' => 'flexible_content',
            'button_label' => '添加布局',
            'layouts' => array(
                'layout_1' => array(
                    'key' => 'layout_1',
                    'name' => 'layout_1',
                    'label' => '布局1',
                    'display' => 'block',
                    'sub_fields' => array(
                        array(
                            'key' => 'field_60d5ea3b8b236',
                            'label' => '选择字段',
                            'name' => 'select_field',
                            'type' => 'select',
                            'choices' => array(
                                'option1' => '选项1',
                                'option2' => '选项2',
                                'option3' => '选项3',
                            ),
                            'default_value' => '',
                            'allow_null' => 0,
                            'multiple' => 0,
                            'ui' => 0,
                        ),
                    ),
                ),
            ),
        ),
    ),
    'location' => array(
        array(
            array(
                'param' => 'post_type',
                'operator' => '==',
                'value' => 'post',
            ),
        ),
    ),
));