Why aren't the Obamas listed as producers of American Factory?

Makes it hard to find other films. It's their Netflix production company.
Seven in total: https://www.nytimes.com/2019/04/30/business/media/obama-netflix-shows.html

American Factory https://www.imdb.com/title/tt9351980/

The first film released from the new production company Higher Ground, founded by former US president Barack Obama and his wife Michelle.