Related to https://progresssoftware.atlassian.net/browse/BLZ-3112
(bug report only)
The issue is also reproducible in the other dropdown components.
(optional)
The aria-activedescendant attribute on the <input> element points to a non-existent element.
The aria-activedescendant attribute on the <input> element must point to the unique id string of the currently active (visually highlighted) <li role="option"> inside the popup listbox. When the popup opens but no item is highlighted (as in the case where the component is not bound to data) the attribute should omitted.