QModbusReply would never finished after QModbusRtuSerialMaster was closed

// code placeholder
void    BlockedModbusMaster::waitFinished (QModbusReply *reply)
{
    if (reply != nullptr)
    {
        while (!reply->isFinished())
        {
            QEventLoop  loop;
            connect(reply, SIGNAL(finished()), &loop, SLOT(quit()), Qt::QueuedConnection);
            connect(reply, SIGNAL(errorOccurred(QModbusDevice::Error)), &loop, SLOT(quit()), Qt::QueuedConnection);

            qDebug("enter loop");
            loop.exec();
            qDebug("exit loop");
        }
    }
}

// code placeholder
QObject::connect(m_serialPort, &QSerialPort::aboutToClose, q, [this]() {
Q_Q(QModbusRtuSerialMaster);
Q_UNUSED(q); // To avoid unused variable warning in release mode
Q_ASSERT(q->state() == QModbusDevice::ClosingState);

m_sendTimer.stop();
m_responseTimer.stop();
});