Email consent not being sent

The function kl_add_to_list is sending data successfully to Klaviyo but it’s not being processed as expected.

Upon inspection I can see:

Sending:

array(1) {
  ["data"]=>
  array(1) {
    [0]=>
    array(5) {
      ["customer"]=>
      array(2) {
        ["email"]=>
        string(26) "## my email ##"
        ["phone"]=>
        string(10) "012356789"
      }
      ["consent"]=>
      bool(true)
      ["updated_at"]=>
      string(25) "2022-11-16T23:28:45+00:00"
      ["consent_type"]=>
      string(5) "email"
      ["group_id"]=>
      string(6) "## group id ##"
    }
  }
}

Result of wp_remote_post is:

["response"]=>
  array(2) {
    ["code"]=>
    int(200)
    ["message"]=>
    string(2) "OK"
  }

Yet email consent status never displays the check mark on the admin panel.

Thanks