Bug White shadow shader and cannot access a disposed object 2020.3.25f1

Posted this in AR forum a few days ago, no response, so I thought I'd try here.

Updated Unity to 2020.3.25f1 and now in my AR project I have white shadow and if I use AR Companion to run the project through the inspector when I touch the screen to place an object I get the red error -

ObjectDisposedException: Cannot access a disposed object.
Object name: 'The NativeArray has been disposed, it is not allowed to access it.

in the below line of code.

Code (CSharp):

1. if (raycastManager.Raycast(touch.position, hits, TrackableType.PlaneWithinPolygon))

But if I run my project in 2020.3.15f2 everything is fine, no errors, and I can place objects.

AR Foundation 4.1.7
ARCore XR Plugin 4.1.7
ARKit XR Plugin 4.1.7

Is it a bug in 2020.3.25f1 ?

Any help would be greatly appreciated.

Kevin.