I only lose the highlight with the touchpad, not when using a mouse. And it only happens after I've had the Dash or the HUD open. Then navigating menus using the touchpad lacks all highlighting. To fix it, I just use the mouse instead, and it works for the touchpad too after that. At least till I open the Dash or HUD again.
Confirmed with unity 5.6.0-0ubuntu1
I only lose the highlight with the touchpad, not when using a mouse. And it only happens after I've had the Dash or the HUD open. Then navigating menus using the touchpad lacks all highlighting. To fix it, I just use the mouse instead, and it works for the touchpad too after that. At least till I open the Dash or HUD again.