Positional Device Tracker is not available.

Hi I have the most basic of Ground Plane Stage set-up but I cannot get it to work on my Huawei Mate20 or my 1Plus6T. I get these 2 errors

Unable to start ObjectTracker. Your hardware may not support it. UnityEngine.Debug:LogError(Object) Vuforia.VuforiaARController:StartAfterInitializationCompleted() Vuforia.VuforiaARController:Start() System.Delegate:DynamicInvoke(Object[]) Vuforia.DelegateHelper:InvokeDelegate(Delegate, Object[]) Vuforia.DelegateHelper:InvokeWithExceptionHandling(Action) Vuforia.VuforiaBehaviour:Start()

Positional Device Tracker is not available. UnityEngine.Debug:LogError(Object) Vuforia.ContentPositioningBehaviour:OnVuforiaStarted() System.Delegate:DynamicInvoke(Object[]) Vuforia.DelegateHelper:InvokeDelegate(Delegate, Object[]) Vuforia.DelegateHelper:InvokeWithExceptionHandling(Action) Vuforia.VuforiaARController:StartAfterInitializationCompleted() Vuforia.VuforiaARController:Start() System.Delegate:DynamicInvoke(Object[]) Vuforia.DelegateHelper:InvokeDelegate(Delegate, Object[]) Vuforia.DelegateHelper:InvokeWithExceptionHandling(Action) Vuforia.VuforiaBehaviour:Start()

I believe I can ignore the first because I don't have any sort of camera set-up on my PC so no wonder that isn't working (Correct me if I'm wrong) but the second one seems to be where the issue is. Can anyone help me out here?

I have added Tracking mode: POSITIONAL so not sure why it wouldn't work. Thanks