It was working fine after setting up ATV, but now nothing happens when I click "Apple TV" on the menu bar icon on my Mac. Tried restarting both Mac and ATV. If I go to System Prefs, it is turning my AirPlay Display to "Off" If I turn it on again by selecting "Apple TV" it's still not doing anything when I go to the select it on the menu bar. When I go back to System Prefs, it's turned off again. Any ideas?