meta_query in WP_Query value is not accepting array

I manually added a “featured” meta key to 2 different posts with values of 1474 and 2213 and then ran a basic WP_Query() like so:

$qv = [
    'meta_query' =>[
        [
            'key'     => 'featured',  
            'value'   => [1474, 2213], 
            'compare' => 'IN',      
        ]
    ] 
];
$r = new WP_Query($qv);

It pulled up both posts. This was query it generated:

SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID 
FROM wp_posts  INNER JOIN wp_postmeta ON ( wp_posts.ID = wp_postmeta.post_id ) 
WHERE 1=1  
AND ( 
    ( wp_postmeta.meta_key = 'featured' AND wp_postmeta.meta_value IN ('1474','2213') )
) 
AND wp_posts.post_type="post" 
AND (wp_posts.post_status="publish" OR wp_posts.post_status="private") 
GROUP BY wp_posts.ID 
ORDER BY wp_posts.post_date DESC 
LIMIT 0, 12

var_dump() out your WP_Query() and see what sql query WP is running.