QState::finished not emitted for parallel QStateMachines

#include <QCoreApplication>
#include <QStateMachine>
#include <QState>
#include <QFinalState>
#include <QAbstractTransition>
#include <QSignalTransition>

QStateMachine *createChildFSM(QCoreApplication& a, QState *parent)
{
    QStateMachine *fsm = new QStateMachine(parent);
    QState *s1 = new QState();
    QFinalState *s2 = new QFinalState();
    fsm->addState(s1);
    fsm->addState(s2);
    fsm->setInitialState(s1);
    s1->addTransition(s2);
    a.connect(s1, &QState::entered, []() \{qDebug() << "Child state 1 entered";});
    a.connect(s2, &QState::entered, []() \{qDebug() << "Child state 2 entered";});
    a.connect(fsm, &QStateMachine::finished, []() \{qDebug() << "Child finished";});
    return fsm;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QStateMachine *fsm = new QStateMachine();
    QState *s1 = new QState(QState::ParallelStates);
    QFinalState *s2 = new QFinalState();

    fsm->addState(s1);
    fsm->addState(s2);
    fsm->setInitialState(s1);

    s1->addTransition(s1, &QState::finished, s2);

    createChildFSM(a, s1);
    createChildFSM(a, s1);

    a.connect(s1, &QState::entered, []() \{qDebug() << "Parent state 1 entered";});
    a.connect(s2, &QState::entered, []() \{qDebug() << "Parent state 2 entered";});

    a.connect(s1, &QState::finished, []() \{qDebug() << "Parent state 1 finished";});

    a.connect(fsm, &QStateMachine::finished, []() \{ qDebug() << "Parent finished"; });
    a.connect(fsm, &QStateMachine::finished, fsm, &QStateMachine::deleteLater);
    a.connect(fsm, &QStateMachine::finished, qApp, &QCoreApplication::quit);

    fsm->start();

    return a.exec();
}