title: the combobox dropdown list is so small that an updown arrows appear beside it
body: <p>I have comboboxes that was built on the OWL I moved them to MFC and I faced alittle problem, the dropdown list of the combobox is so short that it shows only one item and you can navigate to the other items by using udown arrows like in the picture
  <img src="https://i.stack.imgur.com/UbpDq.png" alt="enter image description here"></p>
  
  <p>the image on the left shows the short and incorrect one, the one on the right shows the release version that is working well.
  what can cause this problem? and hoe to fix it. think it is style issue</p>