When the game mode switcher was announced, it was said to have traditional tabbing functionality. Clicking to select is part of that functionality, but doesn't work in the game mode switcher. To reproduce:

1. Bring up the game mode switcher by holding F3 and pressing F4
2. Keep holding F3 and click some game mode with your cursor
3. Observe the highlight change, but not be selected
4. Release the F3 key and observe the game mode change finally be applied