Could not obtain the ARAnchor.nativePtr

I'm currently trying to save a Spatial Anchor to the Azure Spatial Anchor Cloud on an Android device.

The problem
I keep getting the following error:

InvalidOperationException: Could not obtain the ARAnchor.nativePtr

What I've tried
This is my code where I create the Anchor and try to save it on the Azure Spatial Anchor Cloud :

    private async Task CreateAnchor(Vector3 position)
    {
        //...
        GameObject anchorGameObject = GameObject.Instantiate(_CubePrefab);

        anchorGameObject.GetComponent<MeshRenderer>().material.color = Color.white;
        anchorGameObject.transform.position = position;
        anchorGameObject.transform.rotation = orientationTowardsHead;
        anchorGameObject.transform.localScale = Vector3.one * 0.1f;

        //Add and configure ASA components
        CloudNativeAnchor cloudNativeAnchor = anchorGameObject.AddComponent<CloudNativeAnchor>();
        if (cloudNativeAnchor.CloudAnchor == null) { await cloudNativeAnchor.NativeToCloud(); }
        // here is the error it can't do cloudNativeAnchor.NativeToCloud();
        CloudSpatialAnchor cloudSpatialAnchor = cloudNativeAnchor.CloudAnchor;
        cloudSpatialAnchor.Expiration = DateTimeOffset.Now.AddDays(3);

        //...
    }

What I noticed is that I can't make it through await cloudNativeAnchor.NativeToCloud() because it then returns InvalidOperationException: Could not obtain the ARAnchor.nativePtr

I use Unity 2020.3.30f1, ASA 2.13.3, AR Core XR Plugin 4.1.13, MRTK 2.8.2

[UPDATE] I tried also like this :

        //Add and configure ASA components
        CloudNativeAnchor cloudNativeAnchor = anchorGameObject.AddComponent<CloudNativeAnchor>();
     
        // Then we create a new local cloud anchor
        CloudSpatialAnchor cloudSpatialAnchor = new CloudSpatialAnchor();
        // Now we set the local cloud anchor's position to the native XR anchor's position
        cloudSpatialAnchor.LocalAnchor = await anchorGameObject.FindNativeAnchor().GetPointer();
        // Check to see if we got the local XR anchor pointer
        if (cloudSpatialAnchor.LocalAnchor == IntPtr.Zero)
        {
            UnityEngine.Debug.Log("Didn't get the local anchor...");
            return;
        }
        else
        {
            UnityEngine.Debug.Log("Local anchor created");
        }

but the GetPointer() returns null

Adding the following code solved the issue about the pointer being null :

        //Add and configure ASA components
        CloudNativeAnchor cloudNativeAnchor = anchorGameObject.AddComponent<CloudNativeAnchor>();
        if (cloudNativeAnchor.CloudAnchor == null)
        {
            await cloudNativeAnchor.NativeToCloud();
        }

        CloudSpatialAnchor cloudAnchor = cloudNativeAnchor.CloudAnchor;

then the rest of the script is the same as in my post