Query Combo Box Not Populating

In Siebel 16.13, I'm getting an issue with the open ui query combo boxes not having any values. I.e., clicking the combo box does nothing. In the logs, I'm seeing this error:

"Cannot get list of values for radio button control QueryComboBox for applet..."

But I don't see any clues as to what's causing it. It only happens in a few applets -most of them work normally.

To be clear, this is the combo box added in open ui that allows you to select a field to query against on all list applets.

Edit: Regarding the selected answer... Using PopupQueryCombobox in place of QueryComboBox does indeed solve the issue of combo box's LOVs. However, I have found that the PopupQueryCombobox appears to have a default column selected of the first column. The QueryComboBoxes that already work will not have a default search column without specifying one on each applet.