e.FirstVisibleItemIndex returns wrong position if collectionView contains Group

Hello team and hope doing well. I am trying to get e.FirstVisibleItemIndex inside a scrolled Event, using a collectionView with IsGrouped option to true.
Problem is that e.FirstVisibleItemIndex increases by one for each GroupHeader. I found a way which i can skip group header.

var index = e.FirstVisibleItemIndex;
            var categroyName = itemsList2[index].MainGroupItemName;
            var skipedIndex = mCategoryItems.ToList().FindIndex(x => x.MainGroupItemName == categroyName);
            var newIndex = index - skipedIndex;

Is there any more efficient way which i can get real index only from my items and not from groups