Open a drop-down (or start writing in it) and pick a value (click or Tab or Enter)
After the UpdateObject roundtrip the dropdown editor looses focus so it is not possible to use the keyboard to move to the next field (e.g. by pressing Tab).
After picking a value from a dropdown by mouse click or by pressing Enter, the grid editor should stay focused so by pressing Tab afterwards would move it to the next column.
After picking a value by pressing Tab directly from the dropdown, the value should be picked and the next column should be selected afterwards.