Context menus on mac os 12.5.1 are resizeable (and not native in appearance)

On Mac os 12.5.1 "Monterey", using Qt 6.4.0, context menus are resizeable by dragging on a corner or side. They should be a fixed size.

Additionally, since I am reporting this, they do not use a native appearance. Curved corners and translucency are missing, and the layout of QActions in the menu does not have the correct margins. Finally, the separators are drawn too thickly (on a hi dpi screen at least, it appears they are using scaled low dpi pixmaps).

I have attached a 1 minute video file that illustrates these issues in Qt Creator. But they are also replicated in my own projects, so it a Qt thing not a Qt Creator thing. In the video I compare to context menus in a native app, XCode.

Cheers! Best wishes, Mick