Why do I get the "qt.pointer.dispatch" error?

I am making a little app in Qt Creator, and I keep getting this error/warning from qt.pointer.dispatch:

qt.pointer.dispatch: delivering touch release to same window QWindow(0x0) not QWidgetWindow(0x14ef0d570, name="MainWindowWindow")
qt.pointer.dispatch: skipping QEventPoint(id=1 ts=0 pos=0,0 scn=1063.83,670.067 gbl=1063.83,670.067 Released ellipse=(1x1 ∡ 0) vel=0,0 press=-1063.83,-670.067 last=-1063.83,-670.067 Δ 1063.83,670.067) : no target window

I'm not doing anything special with touch release (as you can see below), and the error also doesn't affect the running of the program so far as I can tell. What is the problem and how do I fix it?

main.cpp

#include "mainwindow.hpp"
#include <QApplication>
#include <QLocale>
#include <QTranslator>

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

    QTranslator translator;
    const QStringList uiLanguages = QLocale::system().uiLanguages();
    for (const QString &locale : uiLanguages) {
        const QString baseName = "Simulization_" + QLocale(locale).name();
        if (translator.load(":/i18n/" + baseName)) {
            a.installTranslator(&translator);
            break;
        }
    }
    MainWindow w;
    w.show();
    return a.exec();
}

mainwindow.cpp

#include "mainwindow.hpp"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}