ListView SelectedValue lost after Async updated ItemsSource Item

The WPF app is developed strictly in MVVM pattern

Let's say I have a List included 3 items in ViewModel

var Items = new List<Item> { Item1, Item2, Item3}

<ListViewMargin="5,5,5,20" SelectionMode="Single"	SelectedValue="{Binding SelectedItemObj}"IsSynchronizedWithCurrentItem="True"ItemsSource="{Binding Items, Mode=OneWay}">
And the user click on the grid on Item2
So, the SelectedValue = Item2 
A service async updated the Items collection at seperate thread by 
Items[1] = NewItem;
Because of that, the SelectedValue in the ListView is lost 
And one of the side note is that the async update is very frequent
Please hope if there's anyone who can suggest a solution for me
Million Thanks