To reproduce with the attached test application:
- Run weston or kwin_wayland
- Run the app with --platform wayland
- Press one modifier key (Ctrl, Shift, Alt or Meta)
- Scroll with the mouse wheel
In the wheelEvent() function, QWheelEvent::modifiers() doesn't report the modifiers being held, it just returns NoModifier.
This feature works as expected with --platform xcb.