Steps to reproduce:

1. Open any popup with multiselect (for example, Host edit)
2. Focus on multiselect field (for example, Groups)
3. Enter name for group, that would result in multiple groups in dropdown.
4. Press down arrow to select other group.

Result: Nothing happens.
Expected: Next group in dropdown should be highlighted.

Other hotkeys, like Backspace to delete selected group, or Enter to select group don't work as well.