UISplitViewController appears portrait in landscape mode

Question

I don't mean the master view is hidden in landscape, the whole split controller appears as if it's in portrait mode (If I rotate the device, I can see the rest of the details view). And the master view is hidden (since it's behaving as if the mode is portrait!)

The app works only in landscape mode (left and right).

Answer 1

Well, I found out I was adding a child view controller to the split controller. This ruined the whole split controller. You shall not add any child controller to the split controller itself.