The core parts in QtWayland QPA rely on the assumption that the window will repaint if an expose event is sent.

However, with widgets we observe the opposite sometimes. The QPA sends an expose event but the QWidgetRepaintManager ignores the request (even if the window size has changed!) at https://invent.kde.org/qt/qt/qtbase/-/blob/355e0d85eb4a05acd4d5c9d6b2f1cfce7ccdb144/src/widgets/kernel/qwidgetrepaintmanager.cpp#L619-623. However, the QPA may send an expose event to request new window content even if the size doesn't change, for example when the scale factor changes.

Perhaps the QWidgetRepaintManager could honor all expose events if the exposedWidget is tlw?