I have an app that is a single QGlwidget with a right-click QMenu created when needed.
The data is drawn in an overridden paintEvent()
But in fullscreen mode the menu isn’t displayed.
Am I better having a QGraphicsScene as the parent window and a QGlWidget as the sole child?
There is this bug report on Qt’s bug list which seems related to your issue. The bug describes it as a possible driver issue with NVidia cards. It also looks like there is a workaround.