ImageSource binding resets, image disappears after appearing

I have an image control in one of my app implementation using xamarin forms (2.0), which is binded to an ImageSource

XAML Code:

 <Image x:Name="MyPhoto" Grid.Row="0"
         Grid.Column="0"
         Aspect="AspectFit"
         Source="{Binding ImageSource3}"
         VerticalOptions="CenterAndExpand" WidthRequest="125" >
      <Image.GestureRecognizers>
        <TapGestureRecognizer
            Command="{Binding SelectPictureCommand}" />
      </Image.GestureRecognizers>
    </Image>

When, I tap on the image, it opens the photo album to pick a photo (using xam media plugin). I am able to successfully select the picture. The problem is that the image appears for a split of second in the image control and then it disappears. The same code works well in a different form in the same project. Also this works well in android but gives issue in ios . I am testing using iPhone.

ViewModel Code:

        private async Task SelectPicture()
        {

            try
            {
                var file = await CrossMedia.Current.PickPhotoAsync();  //using xam media plugin
                ImageSource3 = ImageSource.FromStream(() =>
                {
                    var stream = file.GetStream();
                    stream.Position = 0;
                    file.Dispose();
                    return stream;
                });

                mediaFilePath = file.Path;
                uploadImage = true;
            }
            catch (System.Exception ex)
            {

            }
        }

Any help would be appreciable!