When having QWidgets inside of a QOpenGLWidget top level widget there are several update issues.

F.e when changing the geometry ( position, size ) of a QOpenGLWidget its non OpenGL children are not updated on screen ( phantom effects ). When sending an update for those children manually they are displayed correctly, what indicates, that there are only repaints missing.

I have added a short demo. When changing the base class from QOpenGLWidget to QWidget the demo works like expected.