I've used GitHub for years as in individual. I maintain a repository specifically for tracking issues for a team of designers/developers. Recently I setup an organization for my team and transferred the repository of our to do items (issues) into the organization.
On personal repositories I'm able to assign an issue to up to ten people.
Now that the repository is under the control of the organization, the number of people that can be assigned to an issue is limited to one.
I've contacted GitHub directly but have not received a message back. I need to assign issues to more than a single person. Is this not possible if a repo is managed by an organization?