Dyanmic Meta Title and Meta Description not working - Facebook

I have already set in _Root.Head.cshtml
   <title>@Html.NopTitle(false)</title>


And I have added in newsItem.chtml

Html.AddTitleParts(!String.IsNullOrEmpty(Model.NewsItem.MetaTitle) ? Model.NewsItem.MetaTitle : Model.NewsItem.Title);


   Html.AddHeadCustomParts("<meta property=\"og:image\" content=\"" + (string.IsNullOrEmpty(Model.NewsItem.VideoURL) ? Model.NewsItem.PictureModel.FullSizeImageUrl : "") + "\" /> <meta property=\"og:title\" content=\"" + Model.NewsItem.Title + "\" />");


Everything is working fine and also double checked in view stored all looks good but when I try to share the URL in facebook and it is not fetching the title, og:image and descripton.

it always takes default title and description.

Please help