iOS 10: orientation change has no effect

When I rotate my device, the usual methods that were getting called just fine in my apps in iOS 9 are no longer being called:

• traitCollectionDidChange
• viewWillTransitionToSize
• willRotateToInterfaceOrientation
• shouldAutorotateToInterfaceOrientation
• preferredInterfaceOrientationForPresentation

Is there some change that is required to make rotation work again?

Puzzled...