query is affecting 4 rows instead of 2

$sql1 = "SELECT remark FROM log";

          $result1 = mysqli_query($db, $sql1);

          while($row1 = mysqli_fetch_assoc($result1))
          {
                $remark=($row1['remark']);

                $word = "success";
                if (stripos($remark,$word)!== false)
                {

                    $ins = mysqli_query($db,'insert into message_sent SELECT p.batch_id,p.phone,c.remark,p.date,user_id FROM to_numbers p INNER JOIN log c ON c.phone = p.phone');

                }
          }


here i'm executing this query when I execute only sql statement it will affect 2 rows it is correct, If i executed above code it is affecting 4 rows so where is going wrong how can i solve this.