iPad supports screen rotation when you turn the device. This feature helps you seamlessly switch from reading an e-book in portrait mode to watching a movie in landscape mode. If your iPad won’t rotate and is stuck in one position, you can fix it in two ways: in Control Center or with the Side Switch.
iPad Not Rotating? Here’s the Real Fix!
The side switch on iPad controls rotation or mute, depending on how you configure the settings. Any you don’t assign to the side switch will appear in Control Center, where you can turn it on or off.
If your iPad has a side switch, check where the iPad's lock rotation setting is assigned to.
Open the Settings app on your iPad.