Panel Items disappearing after filtering

Question

Greetings I have a combobox which filters all the items in the by clearing the panel controls and repopulating it according to the filter, but for whatever reason it loads them improperly and after a couple of filter changes only shows some and not all. It reads it from a litst passing it to another which has all the filtered ones yet it still cant do it.

Any help is greatly appreciated.

The code segment

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (GegStde == null)
                return;

            foreach (Gegenstand geg in panel1.Controls.OfType<Gegenstand>().Where(x => x.select))
            {
                geg.Reset();
            }

            panel1.Controls.Clear();

            List<Gegenstand> TempGegStd = new List<Gegenstand>();

            if (Filter.SelectedIndex == 0)
                TempGegStd = new List<Gegenstand>(GegStde);
            else if (Filter.SelectedIndex == 1)
                TempGegStd = new List<Gegenstand>(GegStde.Where(x => x.GetDesc.Contains("Spezies")).ToList());
            else if (Filter.SelectedIndex == 2)
                TempGegStd = new List<Gegenstand>(GegStde.Where(x => !x.GetDesc.Contains("Spezies")).ToList());

            foreach (Gegenstand art in TempGegStd)
            {

                panel1.Controls.Add(art);

                if (panel1.Controls.Count > 1)
                    art.Location = new Point(art.Location.X, panel1.Controls[panel1.Controls.Count - 2].Location.Y + panel1.Controls[panel1.Controls.Count - 2].Height + 5);
            }
        }