get_fields doesn’t work as well with dummy data in phpunit

In unit tests I have the problem when use factory class of the unit test for create dummy data in test DB.

$id = $this->factory->post->create(
            [
                'post_title' => 'test_acf',
                'post_name'  => 'test_acf',
            ]
        );

add_post_meta( $id, 'my_key1', 1 );
add_post_meta( $id, 'my_key2', 2 );
add_post_meta( $id, 'my_key3', 3 );

After that we can get post meta with get_post_meta($id, 'my_key1');
But get_fields($id); doesn’t works as well. It’s return just false.