I am attempting to query posts based on the value of a repeater subfield dropdown (select field) but am having trouble.

Here is what I am working with:

<?php
    // Set up the arguments for the query
    $args = array(
    'meta_query' => array(
      array(
          'key' => 'groups_and_committees_selector_$_committees_groups', // name of the ACF subfield
          'value' => 'Board of Directors', // value to filter by
          'compare' => '=' // comparison operator
            )
        )
    );
    $user_query = new WP_User_Query($args); // Create the WP_User_Query object
    $users = $user_query->get_results();// Get the results
    foreach ( $users as $user ) {  // Loop through the users
       echo 'User Name: ' . $user->user_firstname . '<br>'; // Display the user's login name
    }
?>

This is not returning any results. If I try the above code but use a standard field key of “test” and value of “true” it returns the two users I setup for that test correctly.

I am guessing there is an issue with my key or my value but I cannot figure it out.

What am I doing wrong in my code?