Selected item in dropdown does not get highlighted the next time I click on the dropdown

Question

I have tried searching for a solution but could not come to one. The item selected from the combo box is not getting highlighted the second time I click on the drop down.

Example: suppose I have selected an item named dog from the combo box, now when I click the drop down, the control should be in on dog but that is not happening, instead again I have to scroll through the entire list in the drop down to get to the item dog.

 void Part::OnCbnSelchangeItemcombo()
 {
   CComboBox* pitem = (CComboBox*)GetDlgItem(IDC ITEM_COMBO);
   int CurrentSelection = psize->GetCurSel();
   pitem->GetLBText(CurrentSelection,SelectedItem);
   SelectedItem.Trim();
 }