When using a QOpenGLWidget as the viewport for a QGraphicsView then it is not calling paintGL automatically, therefore nothing is rendered even if it is updating

When using a QOpenGLWidget as the viewport for a QGraphicsView then it is not calling paintGL automatically, therefore nothing is rendered even if it is updating. A manual update needs to be done instead to force it to render. When using a QGLWidget then it is working fine. The example attached is a modified qopenglwidget example to use QGraphicsView.