I have noticed that when you have dddw or ddlb with the allow-editing attribute on and the autocomplete mode suggest/append (3) on, and then type in a value that partially matches one or more items in the dropdown list, and then backspace out of the editing, causing the full list to appear again, the values that were partially matched remain at the top of the list, and the rest of the list is not necessarily in the order they were in before the search. This seems like a bug to me, but maybe it is by design? I would expect the dropdown list to return to its original sort order after removing the edit-search.
drop down list before any searching
drop down list while searching
drop down list after backspacing out the search letters