Reproduction steps:
1. Open the user's attached "Unity URP Quest2 XR Test v3.zip" project
2. Load the SampleScene
3. Enter Play mode
4. Press Alt+Y on the keyboard
5. Observe the Console window

Expected result: the "Cannot set field of view on camera with name 'Main Camera' while VR is enabled" warning is logged once
Actual result: the "Cannot set field of view on camera with name 'Main Camera' while VR is enabled" warning is being spammed

Reproducible with: URP 7.5.3 (2019.4.21f1), 9.0.0-preview.72 (2020.2.0b1)
Not reproducible with: URP 10.0.0-preview.26 (2020.2.0b1), 10.3.2 (2020.2.7f1, 2020.3.0f1), 11.0.0 (2021.1.0b11), 12.0.0 (2021.2.0a8)
Could not test with 2018.4.(no URP package available)

Note: the whole warning message that is spammed:
Cannot set field of view on camera with name 'Main Camera' while VR is enabled.
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Cinemachine.CinemachineBrain:PushStateToUnityCamera (Cinemachine.CameraState) (at Library/PackageCache/com.unity.cinemachine@2.6.3/Runtime/Behaviours/CinemachineBrain.cs:823)
Cinemachine.CinemachineBrain:ProcessActiveCamera (single) (at Library/PackageCache/com.unity.cinemachine@2.6.3/Runtime/Behaviours/CinemachineBrain.cs:609)
Cinemachine.CinemachineBrain:ManualUpdate () (at Library/PackageCache/com.unity.cinemachine@2.6.3/Runtime/Behaviours/CinemachineBrain.cs:366)
Cinemachine.CinemachineBrain:LateUpdate () (at Library/PackageCache/com.unity.cinemachine@2.6.3/Runtime/Behaviours/CinemachineBrain.cs:323)

Tested with:
- Oculus Rift