Alternative Dates Display

Hello, I was recently in touch asking how to show related events when you had selected date in the booking calendar on the event details page and was given the following queries to try:

function get_other_events( $child_event_id, $limit ) {
  $child_event = get_post( $child_event_id );

  $other_child_events = get_posts( array(
    'post_type' => 'qsot-event',
    'post_status' => 'publish',
    'post_parent' => $child_event->post_parent,
    // events that start in the future
    'meta_query' => array(
      array(
        'key' => '_start',
        'value' => date( 'c' ), // now
        'compare' => '>',
      ),
    ),
    'meta_key' => '_start',
    'orderby' => 'meta_value',
    'meta_type' => 'DATETIME',
  ) );

  return $other_child_events;
}

and

function get_other_events( $child_event_id, $limit ) {
  $child_event = get_post( $child_event_id );
  $event_area_id = get_post_meta( $child_event->ID, '_event_area_id', true );

  $other_child_events = get_posts( array(
    'post_type' => 'qsot-event',
    'post_status' => 'publish',
    // events that start in the future
    'meta_query' => array(
      array(
        'key' => '_event_area_id',
        'value' => $event_area_id,
      ),
      array(
        'key' => '_start',
        'value' => date( 'c' ), // now
        'compare' => '>',
      ),
    ),
    'meta_key' => '_start',
    'orderby' => 'meta_value',
    'meta_type' => 'DATETIME',
  ) );

  return $other_child_events;
}

but one returns the other events available and one returns no results at all. could you help?