It was good while it lasted...Discovery GO used to be an app that combined all of Discovery's channels. Now Discovery has has separated the channels and created individual apps for each channel. So instead of one single combined app, there's now 9 individual apps (oh joy):
-Discovery GO
-TLC GO
-Animal Planet GO
-Investigation Discovery GO
-Science Channel GO
-Discovery Life GO (no tvOS app yet)
-Velocity GO (no tvOS app yet)
-AHC GO (no tvOS app yet)
-Destination America GO (no tvOS app yet)
So if you watch any of the four channels that don't have tvOS apps yet (Discovery Life, Velocity, AHC, or Destination America), you'll need to airplay the IOS app to the Apple TV since the content and live streams of those channels have been removed from the Discovery GO tvOS app. You'll need to do this until Discovery gets around to creating tvOS apps for those channels.
-Discovery GO
-TLC GO
-Animal Planet GO
-Investigation Discovery GO
-Science Channel GO
-Discovery Life GO (no tvOS app yet)
-Velocity GO (no tvOS app yet)
-AHC GO (no tvOS app yet)
-Destination America GO (no tvOS app yet)
So if you watch any of the four channels that don't have tvOS apps yet (Discovery Life, Velocity, AHC, or Destination America), you'll need to airplay the IOS app to the Apple TV since the content and live streams of those channels have been removed from the Discovery GO tvOS app. You'll need to do this until Discovery gets around to creating tvOS apps for those channels.