Can not input Chinese in TextEdit when load qml in QQuickWidget

I have a project that developed by QWidget, and when I add a new feature, I used QML. By creating a QQuickWidget and added it into QWidget, I found a way to combine QML widgets  with my old QMainWindow.

But the TextEdit that create in QQuickWidget can not input Chinese! Only after minimize the  and reactive the main window that I can input Chinese.

The project in Attachment is a simple demo that add a TextEdit in Rectange, and display the QML widgets in QQuickWidget.