Cannot navigate through options in combo box

Cannot navigate through options in combo box with the default navigation. This appears to be a regression.

Working as expected in 4.15.3
No longer working as expected in 4.16

1. Open the editor
2. Create a new widget blueprint
3. Add a combo box to the designer tab
4. Add 5 options to the combo box
5. Create the blueprint in the attached image
6. Save and compile
7. Open the level blueprint
8. Add the widget that was created to the view port
9. Play in editor
10. Press the enter key
11. Notice that the combo box opens (showing that it has focus)
12. Press the up and down arrow keys to scroll through the options
13. Notice that you are unable to navigate the selected options available in the combo box

Expected: The arrow keys (or game pad) would be able to navigate through the drop down list when the combo box is open
Result: The user is unable to navigate through the options in the combo box