Steps to reproduce
- Set up a translucent window as shown below.
- Drag the window around.
- Minimize + restore the window.
- Goto 2
"Phantom" images form within the window. Minimizing (or obscuring) the window resets things to normal, until the window is moved again.
I couldn't improve things by playing around with QQuickWindow::setDefaultAlphaBuffer() or QQuickWindow::clearBeforeRendering().