Confusing WP Query's with ACF

query-acf.php

# Querying a relationship field (stored as a serialized array)
# https://www.advancedcustomfields.com/resources/querying-relationship-fields/

$related_posts = get_posts([
    'post_type' => ['publication'],
    'posts_per_page' => 6,
    'meta_query' => [
        [
            'key' => 'related_research_area',
            'value' => $cur_id,
            'compare' => 'LIKE'
        ]
    ]
]);