To reproduce:
- Initialize the control like this:
public Form1()
{
    InitializeComponent();
    this.radListView1.ListViewElement.Children[0].Children[0].Padding = new Padding(0, 0, 50, 0);
    this.radListView1.ListViewElement.BackColor = Color.FromArgb(255, 2, 48, 108);
    this.radListView1.ItemSpacing = 10;
    this.radListView1.ItemSize = new Size(152, 152);
    this.radListView1.AllowArbitraryItemHeight = false;
    this.radListView1.AllowArbitraryItemWidth = false;
}

private void Form1_Load(object sender, EventArgs e)
{
    for (int i = 1; i < 23; i++)
    {
        ListViewDataItem item = new ListViewDataItem();
        item.Text = "The7quick7brown7fox7jumps7over7the7lazy7dog";
        item.NumberOfColors = 1;
        item.BackColor = Color.FromArgb(255, 106, 90, 167);
        item.ForeColor = Color.White;

        this.radListView1.Items.Add(item);
    }
}

- Resize the form in such way that there is a free space on the right side of the items.
- Maximize and then restore the form.
- The space is gone.