High cpu usage when moving a gui containing a QtWebEngine and WA_TranslucentBackground

Cesar

Could someone else confirm this bug happens on your side?
https://bugreports.qt.io/browse/QTBUG-109676

In my project containing many widgets, it happens 100% of the time, making my GUI freeze when I move it.

To reproduce the bug:

#include <QtWebEngineWidgets/QWebEngineView>

QtWidgetsApplication::QtWidgetsApplication(QWidget *parent)
    : QMainWindow(parent)
{
    ui.setupUi(this);

    setAttribute(Qt::WA_TranslucentBackground);

	QGridLayout* layout = new QGridLayout(ui.centralWidget);
  
    QShortcut *shortcut = new QShortcut(QKeySequence(Qt::Key_F2), this);
    connect(shortcut, &QShortcut::activated, [this]
    {
        qDebug() << "shortcut";
        QWebEngineView* engine = new QWebEngineView();  
        QGridLayout* layout = qobject_cast<QGridLayout*>(ui.centralWidget->layout());
        layout->addWidget(engine); 
    });
}

Press F2 and move the GUI around, here CPU change from 2% to 10%~
When testing sometimes it happened only after I reload the GUI many times and sometimes it happened consecutively.

Notes:
I also tested it outside Visual Studio by running the compiled exe directly.
Tested on 3 different machines, and Windows 10/11.

Cesar

Someone else?