$itemId = $parentTicket[0]['id'];

function bubbleSort(&$arr)
{
    $n = sizeof($arr);

    for($i = 0; $i < $n; $i++)
    {
        for ($j = 0; $j < $n - $i - 1; $j++)
        {
            if ($arr[$j] > $arr[$j+1])
            {
                $t = $arr[$j];
                $arr[$j] = $arr[$j+1];
                $arr[$j+1] = $t;
            }
        }
    }
}

//$pos_sql = "select position from protocol_item where protocol_item.protocol = $itemId";
$pos_sql = "SELECT item.id, item.protocol, item.position, item.subject_item, item.type, item.responsible, item.INSDATE, item.body, pp.participant, p.subject, p.status FROM protocol p LEFT JOIN protocol_item item ON item.protocol = p.id LEFT JOIN protocol_participant pp ON pp.itemid = item.id WHERE item.protocol = $itemId GROUP BY item.id";
$arr = $global->db->getQuery($pos_sql);
//$arr = array(64, 34, 25, 12, 22, 11, 90); // it's working

$len = sizeof($arr);
bubbleSort($arr);

echo "Sorted array : n";

for ($i = 0; $i < $len; $i++) {
     $final_position = $arr[$i];
     echo $final_position . " ";

}

Array
(
    [0] => Array
        (
            [id] => 15
            [protocol] => 12
            [position] => 2
            [subject_item] =>
            [type] => D
            [responsible] => Chonchol
            [INSDATE] => 2019-07-03 11:33:13
            [body] => With responsible
            [participant] => Chonchol,Mahmud,more
            [subject] => Check for multi-participant final
            [status] => 0
        )

    [1] => Array
        (
            [id] => 16
            [protocol] => 12
            [position] => 2
            [subject_item] =>
            [type] => D
            [responsible] => Mahmud
            [INSDATE] => 2019-07-03 11:39:01
            [body] => With Responsible
            [participant] => Donald,Trump,Brad,Pitt
            [subject] => Check for multi-participant final
            [status] => 0
        )

    [2] => Array
        (
            [id] => 17
            [protocol] => 12
            [position] => 6
            [subject_item] =>
            [type] => I
            [responsible] => Testing
            [INSDATE] => 2019-07-03 11:43:01
            [body] => Another body bcfb
            [participant] =>
            [subject] => Check for multi-participant final
            [status] => 0
        )

    [3] => Array
        (
            [id] => 21
            [protocol] => 12
            [position] => 1
            [subject_item] => This is form Update
            [type] => S
            [responsible] => three
            [INSDATE] => 2019-07-13 04:39:10
            [body] => ffffffffffff
            [participant] =>
            [subject] => Check for multi-participant final
            [status] => 0
        )

)