QOpenGLWidget affect QMenu when showFullScreen()

Developing in Windows 10
Running in Windows 7 32bit

1 Create a GUI example with QMainwindow(other is same), place a QOpenGLWidget on UI , and add some menu on UI.
2 add setWindowFlag(Qt::FramelessWindowHint);
code as :
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)

{ ui->setupUi(this); this->setWindowFlag(Qt::FramelessWindowHint); }

3 change show to showMaximized;
code is :
int main(int argc, char *argv[])

{ QApplication a(argc, argv); MainWindow w; // w.show(); w.showMaximized(); return a.exec(); }

and then run , something looks ok.

when you use windeployqt eeee.exe, and copy these to anthoer PC，and double click the exe, click menu ,but the Menu not show.
likes Qt 5.11.

If you delete QOpenGLWidget, everything is OK.

my app always showMaximized() or showFullScreen() , the bug make me miss a lot of projects