Widget takes a long time until it starts to receive mouse events in full screen mode on macOS

/**
 * main.cpp
 */

#include <QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[]) {
    QApplication a(argc, argv);
    MainWindow mainWindow;
    mainWindow.show();
    return QApplication::exec();
}


/**
 * mainwindow.h
 */

#pragma once

#include "popupwindow.h"
#include <QWidget>
#include <QPushButton>

class MainWindow : public QWidget
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);

private slots:
    void handleFullScreenButton();
    void handleNormalScreenButton();

private:
    PopupWindow* m_fullScreenWindow;
    QPushButton* m_fullScreenButton;
    QPushButton* m_normalScreenButton;
    PopupWindow* m_normalScreenWindow;
};


/**
 * popupwindow.h
 */

#pragma once

#include <QWidget>
#include <QLabel>

class PopupWindow : public QWidget
{
    Q_OBJECT

public:
    explicit PopupWindow(QWidget* parent = nullptr);

protected:
    void mouseMoveEvent(QMouseEvent *event) override;
    void mousePressEvent(QMouseEvent *event) override;

private:
    void showText(const QString &text);
    QLabel* m_text;
    qint64 m_creationTimestamp;
    bool m_eventReceived;
};


/**
 * mainwindow.cpp
 */

#include "mainwindow.h"
#include <QDebug>
#include <QVBoxLayout>

MainWindow::MainWindow(QWidget *parent)
    : m_normalScreenWindow(nullptr)
    , m_fullScreenWindow(nullptr)
{
    auto *layout = new QVBoxLayout(this);
    m_normalScreenButton = new QPushButton("Popup screen");
    m_fullScreenButton = new QPushButton("Popup full screen");
    connect(m_normalScreenButton, &QPushButton::released, this, &MainWindow::handleNormalScreenButton);
    connect(m_fullScreenButton, &QPushButton::released, this, &MainWindow::handleFullScreenButton);
    layout->addWidget(m_normalScreenButton);
    layout->addWidget(m_fullScreenButton);
}

void MainWindow::handleNormalScreenButton() {
    m_normalScreenWindow = new PopupWindow(this);
    m_normalScreenWindow->show();
    m_normalScreenWindow->activateWindow();
    m_normalScreenWindow->raise();
}

void MainWindow::handleFullScreenButton() {
    m_fullScreenWindow = new PopupWindow(this);
    m_fullScreenWindow->showFullScreen();
    m_fullScreenWindow->activateWindow();
    m_fullScreenWindow->raise();
}


/**
 * popupwindow.cpp
 */

#include "popupwindow.h"
#include <QDateTime>
#include <QDebug>
#include <QHBoxLayout>

PopupWindow::PopupWindow(QWidget *parent)
    : m_creationTimestamp(QDateTime::currentMSecsSinceEpoch())
    , m_eventReceived(false)
    , m_text(nullptr)
{
    setAttribute(Qt::WA_DeleteOnClose);
    setMouseTracking(true);
}

void PopupWindow::mouseMoveEvent(QMouseEvent *event) {
    if (m_eventReceived) {
        return;
    }
    auto deltaTimeMs = QDateTime::currentMSecsSinceEpoch() - m_creationTimestamp;
    showText(QString("First mouse event received after %1 ms.").arg(deltaTimeMs));
    m_eventReceived = true;
}

void PopupWindow::mousePressEvent(QMouseEvent *event) {
    showNormal();
    close();
}

void PopupWindow::showText(const QString &text) {
    m_text = new QLabel(text);
    m_text->setStyleSheet("font: 26pt;");
    auto *layout = new QVBoxLayout(this);
    layout->addWidget(m_text, Qt::AlignCenter);
}