Screen garbled after first change of LnF in examples/widgets/icons with OpenGL

When running "examples/widgets/icons/icons -graphicssystem opengl" the screen is usually garbled after first attempt to change the look and feel in the View menu item (e.g. Plastique). Interacting with a GUI widget can provoke a correctly looking redraw of that widget. Continue changing between the different items in the view menu and then the different LnFs render correctly each time. The initial LnF that loads (Windows) works fine every time the application is started. The issue does not occur with software rendering.

Attached before choosing a LnF (Plastique) and after choosing a LnF but with a few widgets redrawn correctly.

Not sure what causes this.