Add post format support not working

I am working on a theme and for some reason, add_theme_support( 'post-formats', ... ) is not working.

In my theme’s functions.php I have the following near the top:

    function mytheme_setup() {
        // ...other functions

        // Add post formats support
        add_theme_support( 'post-formats', array(
            'aside',
            'audio',
            'chat',
            'gallery',
            'image',
            'link',
            'quote',
            'status',
            'video',
        ) );

        // ... more other functions
    }
    add_action( 'after_setup_theme', 'mytheme_setup' );

    add_post_type_support( 'post', 'post-formats' );

Yet, when I go to WordPress admin -> Posts -> Edit New Post or Add New Post, I do not see a box allowing me to select a post format. I tried putting add_post_type_support() inside mytheme_setup() function, but still the same result. Am I missing something?