Default Filters in list-view: different type of search boxes?

In the Item price, the headers have the search boxes:

ID, Item Code, Item Name, Price List, Reference.

in ID and Item name, as I type, the data gets filtered automatically and no pop up windows for selection, while in item code, it pop ups a windows for selection but doesn’t the data doesn’t get filtered automatically as I type.

How can we make the Item Code to filter the data as I type rather than having a pop-up list appearing for selection?