QWindow::startSystemMove() has problem with Windows OS

1. When startSystemMove() is triggered with a single click (not dragging), the UI elements freeze. The freeze is corrected when the next content scene is clicked.

2. Using startSystemMove() with window flags Qt::FramelessWindowHint or Qt::CustomizeWindowHint disables Windows edge snapping and window animations such as maximize, minimize, and close window. This issue is likely related to the window title (WS_CAPTION). When I disable WS_CAPTION using SetWindowLongA()(from windows.h), snapping and animations stop, similar to the issue described in item 2.

reproduction code included.