DevExpress ThemedWndow prism customregion adapter prism 8 core 3.1

[stevensrf11]

I am having trouble in getting a custom regionadapter to work with a devexpress ThemedWindow.
Does anyone have a prior demo projects that has a PRISM custom regionadapter that work successfully placing a ThemedWindow in a named region?

Below is the custom regionadapter I wrote for a ThemedWindow with the ThemedWindow being registered in PRISM, but it does not seem to work.
If anyone has any suggestions I would be of interest.

public class DxThemedWindowRegionAdapter : RegionAdapterBase<ThemedWindow>
{
    public DxThemedWindowRegionAdapter(IRegionBehaviorFactory regionBehaviorFactory)
        : base(regionBehaviorFactory)
    {
    }
    /// <summary>
    /// Adapts a <see cref="ThemedWindow"/> to an <see cref="IRegion"/>.
    /// </summary>
    /// <param name="region">The new region being used.</param>
    /// <param name="regionTarget">The object to adapt.</param>
    protected override void Adapt(IRegion region, ThemedWindow regionTarget)
    {
        if (regionTarget == null) throw new ArgumentNullException("regionTarget");
        bool contentIsSet = regionTarget.Content != null;
        contentIsSet = contentIsSet || (BindingOperations.GetBinding(regionTarget, ThemedWindow.ContentProperty) != null);

        if (contentIsSet)
        {
            throw new InvalidOperationException("ContentControlHasContentException");
        }

        region.ActiveViews.CollectionChanged += delegate
        {
            regionTarget.Content = region.ActiveViews.FirstOrDefault();
        };

        region.Views.CollectionChanged +=
            (sender, e) =>
            {
                if (e.Action == NotifyCollectionChangedAction.Add && region.ActiveViews.Count() == 0)
                {
                    region.Activate(e.NewItems[0]);
                }
            };
    }

    protected override IRegion CreateRegion()
    {
        //??new AllActiveRegion()
        return new SingleActiveRegion();
    }

}

protected override void ConfigureRegionAdapterMappings(RegionAdapterMappings regionAdapterMappings)
    {
        base.ConfigureRegionAdapterMappings(regionAdapterMappings);
        // Custom Adapters


        regionAdapterMappings.RegisterMapping(typeof(ThemedWindow),
                        Container.Resolve<DxThemedWindowRegionAdapter>());
    }