Deleting items from list in uwp

I am trying to delete items from my list on click of delete button but clicking once the list only gets refreshed and clicking again deletes item from the list. Here is my code:

private void AppBarButton_Click(object sender, RoutedEventArgs e)
    {
        var query = BreakfastList.SelectedItems;
        foreach (var item in query)
        {
            conn.Delete(item);
        }
        if (Item1.IsSelected)
        {
            List<DbManager> people = (from p in conn.Table<DbManager>()
                                      select p).OrderByDescending(q => q.id).ToList();
            BreakfastList.ItemsSource = people;
        }
        else if (Item2.IsSelected)
        {
            List<DbManager> people = conn.Table<DbManager>().OrderByDescending(q => q.id).Where(q => q.Reading == "Breakfast").ToList();
            BreakfastList.ItemsSource = people;
        }
        else if (Item3.IsSelected)
        {
            List<DbManager> people = conn.Table<DbManager>().OrderByDescending(q => q.id).Where(q => q.Reading == "Lunch").ToList();
            BreakfastList.ItemsSource = people;
        }
        else if (Item4.IsSelected)
        {
            List<DbManager> people = conn.Table<DbManager>().OrderByDescending(q => q.id).Where(q => q.Reading == "Dinner").ToList();
            BreakfastList.ItemsSource = people;
        }
    }

Item1,2,3,4 are items in my combobox