Steps to reproduce:
1. Open the attached project
2. Open the CinemachineOrbitalTransposer Scene
3. Enter Play Mode

Reproducible with: 2022.1.0b5
Not reproducible with:

Expected result: there are no errors
Actual Result: the following error is thrown because the old UnityEngine.Input is being used directly from the Cinemachine code even though the new Input System is enabled.

InvalidOperationException: You are trying to read Input using the UnityEngine.Input class, but you have switched active Input handling to Input System package in Player Settings.
Cinemachine.AxisState.Update (System.Single deltaTime) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Core/AxisState.cs:224)
Cinemachine.CinemachineOrbitalTransposer.UpdateHeading (System.Single deltaTime, UnityEngine.Vector3 up, Cinemachine.AxisState& axis, Cinemachine.AxisState+Recentering& recentering, System.Boolean isLive) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Components/CinemachineOrbitalTransposer.cs:223)
Cinemachine.CinemachineOrbitalTransposer+<>c.<.ctor>b__30_0 (Cinemachine.CinemachineOrbitalTransposer orbital, System.Single deltaTime, UnityEngine.Vector3 up) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Components/CinemachineOrbitalTransposer.cs:178)
Cinemachine.CinemachineOrbitalTransposer.MutateCameraState (Cinemachine.CameraState& curState, System.Single deltaTime) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Components/CinemachineOrbitalTransposer.cs:366)
Cinemachine.CinemachineVirtualCamera.CalculateNewState (UnityEngine.Vector3 worldUp, System.Single deltaTime) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Behaviours/CinemachineVirtualCamera.cs:524)
Cinemachine.CinemachineVirtualCamera.InternalUpdateCameraState (UnityEngine.Vector3 worldUp, System.Single deltaTime) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Behaviours/CinemachineVirtualCamera.cs:155)
Cinemachine.CinemachineCore.UpdateVirtualCamera (Cinemachine.CinemachineVirtualCameraBase vcam, UnityEngine.Vector3 worldUp, System.Single deltaTime) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Core/CinemachineCore.cs:355)
Cinemachine.CinemachineCore.UpdateAllActiveVirtualCameras (System.Int32 layerMask, UnityEngine.Vector3 worldUp, System.Single deltaTime) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Core/CinemachineCore.cs:275)
Cinemachine.CinemachineBrain.UpdateVirtualCameras (Cinemachine.CinemachineCore+UpdateFilter updateFilter, System.Single deltaTime) (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Behaviours/CinemachineBrain.cs:427)
Cinemachine.CinemachineBrain.ManualUpdate () (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Behaviours/CinemachineBrain.cs:376)
Cinemachine.CinemachineBrain.LateUpdate () (at Library/PackageCache/com.unity.cinemachine@2.8.4/Runtime/Behaviours/CinemachineBrain.cs:336)