Android Palette working only on some of RecyclerView items

I'm trying to generate a Palette for each CardView I have inside a RecyclerView, and to color the card based on the Palette generated.
However, for some weird reason, only the last two CardViews of the RecyclerView get colored.

This is my code:

RecyclerAdapter:

 public class RecyclerAdapter : RecyclerView.Adapter, Palette.IPaletteAsyncListener
{
    private List<Book> mBooks;
    private RecyclerView mRecyclerView;
    private Context mContext;
    private int mCurrentPosition = -1;
    private bool isPaletteGenerated = false;
    MyView myHolder;
    public RecyclerAdapter(List<Book> books, RecyclerView recyclerView, Context context)
    {
        mBooks = books;
        mRecyclerView = recyclerView;
        mContext = context;
    }

    public class MyView : RecyclerView.ViewHolder
    {
        public View mMainView { get; set; }
        public TextView mTitle { get; set; }
        public ImageView mCoverImage { get; set; }
        public int mCoverImageResourceID { get; set; }
        public CardView mCard { get; set; }

        public MyView(View view) : base(view)
        {
            mMainView = view;
        }
    }

    public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
    {

        View bookItem = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.item_book, parent, false);


        TextView bookTitle = bookItem.FindViewById<TextView>(Resource.Id.bookTitle);
        ImageView coverImage = bookItem.FindViewById<ImageView>(Resource.Id.coverImage);
        CardView card = bookItem.FindViewById<CardView>(Resource.Id.card);

        MyView view = new MyView(bookItem) { mTitle = bookTitle, mCoverImage = coverImage, mCard = card};
        return view;
    }

    public override async void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
    {
        myHolder = holder as MyView;
        myHolder.mMainView.Click += mMainView_Click;
        myHolder.mTitle.Text = mBooks[position].Title;
        myHolder.mCoverImage.SetImageDrawable(mBooks[position].Cover.Drawable);
        myHolder.mCoverImageResourceID = mBooks[position].imageResourceId;

        if (position > mCurrentPosition)
        {
            int currentAnim = Resource.Animation.slide_left_to_right;
            //SetAnimation(myHolder.mMainView, currentAnim);
            mCurrentPosition = position;
        }

        Bitmap photo = await BitmapFactory.DecodeResourceAsync(mContext.Resources, myHolder.mCoverImageResourceID);
        BitmapDrawable bitmapDrawable = ((BitmapDrawable)mBooks[position].Cover.Drawable);
        Bitmap image = bitmapDrawable.Bitmap;

        var palette = Palette.From(photo).MaximumColorCount(16).Generate(this);


    }   

    public void OnGenerated(Palette palette)
    {

        if (palette == null)
            return;
        try
        {
            if (palette.LightVibrantSwatch != null)
            {
                var lightVibrant = new Color(palette.LightVibrantSwatch.Rgb);
                myHolder.mCard.SetCardBackgroundColor(lightVibrant);
            }
            if (palette.DarkVibrantSwatch != null)
            {
                var darkVibrant = new Color(palette.DarkVibrantSwatch.Rgb);
                myHolder.mCard.SetCardBackgroundColor(darkVibrant);
            }
        }
        catch (Exception ex)
        {

        }

    }

    public override int ItemCount
    {
        get { return mBooks.Count; }
    }
}

Fragment in which the RecyclerView is inside:

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{

    mRecyclerView = view.FindViewById<RecyclerView>(Resource.Id.booksRecyclerView);
    mBooks = new List<Book>();
    ImageView cover = new ImageView(Activity);

    cover.SetImageResource(Resource.Drawable.Torat_Hamachane1);
    mBooks.Add(new Book() { Title = "תורת המחנה א' - הלכות יום ויום", Cover = cover, imageResourceId = Resource.Drawable.Torat_Hamachane1}); 


    mLayoutManager = new GridLayoutManager(Activity, 2);
    mRecyclerView.SetForegroundGravity(GravityFlags.CenterHorizontal);
    mRecyclerView.SetLayoutManager(mLayoutManager);
    SimpleItemAnimator x = null;

    mRecyclerView.SetItemAnimator(x);
    mAdapter = new RecyclerAdapter(mBooks, mRecyclerView, Activity);
    mRecyclerView.SetAdapter(mAdapter);


    cover = new ImageView(Activity);
    cover.SetImageResource(Resource.Drawable.kitzurTHM);
    mBooks.Add(new Book() { Title = "קיצור תורת המחנה - הלכות יום ויום ושבת", Cover = cover, imageResourceId = Resource.Drawable.kitzurTHM });

    cover = new ImageView(Activity);
    cover.SetImageResource(Resource.Drawable.halkasPurim);
    mBooks.Add(new Book() { Title = "הלכה כסדרה - הלכות פורים", Cover = cover, imageResourceId = Resource.Drawable.halkasPurim });

    cover = new ImageView(Activity);
    cover.SetImageResource(Resource.Drawable.halkasPesach);
    mBooks.Add(new Book() { Title = "הלכה כסדרה - הלכות פסח", Cover = cover, imageResourceId= Resource.Drawable.halkasPesach });

    cover = new ImageView(Activity);
    cover.SetImageResource(Resource.Drawable.netzach);
    mBooks.Add(new Book() { Title = "שו\"ת נצח יהודה", Cover = cover , imageResourceId = Resource.Drawable.netzach});

    cover = new ImageView(Activity);
    cover.SetImageResource(Resource.Drawable.tankim);
    mBooks.Add(new Book() { Title = "טיפול בטנקים בשבת", Cover = cover , imageResourceId = Resource.Drawable.tankim});

    cover = new ImageView(Activity);
    cover.SetImageResource(Resource.Drawable.tipulBeChalalim);
    mBooks.Add(new Book() { Title = "טיפול בחללים בשבת", Cover = cover , imageResourceId = Resource.Drawable.tipulBeChalalim});
    return view;

}

Hope someone can please help me find out why only the last two items get colored.

Thanks!

Anyone?