QML Types tab of item library only has flow tags on freshly created project

Create a new "General/Qt Quick Application - Empty" project. When the designer mode opens after project creation, the item library QML Types tab only has flow tags, but is otherwise empty. There should be various items supported by default imports visible. Adding any import makes the items appear.

This only happens when a new project is created. When project is loaded, it'll show the items properly.