Assigning itemsource to private property of listview not working please guide

<ListView x:Name="listview"ItemsSource="{Binding NewDeviceSessionList}"SelectedItem="{Binding DeviceSession, Mode=TwoWay}">
`private List newDeviceSessionlist;

    public List<DeviceSession> NewDeviceSessionList
    {
        get => newDeviceSessionlist;
        set => SetProperty(ref newDeviceSessionlist, value);
    }

//Not working
newDeviceSessionlist=listsource

//Working
NewDeviceSessionList=listsource`