I can reproduce this in a simple application, but you can check it directly in one of the demos:

1. Run the qtdemo -> tools -> undoframework and launch the demo.
2. Add a few items (triangles, boxes)
3. Select the undoview window (command list) and use the keyboard up/down cursor to navigate the stack.

Although the undostack is updated, by the visual feedback on the main window, the selected line remains at the top.
Using the mouse to select a line works fine.