We have a team with 8 users. All have admin access. We have a number of private repositories. Some where created as user-repos and afterwards transfered to the team.
When a user who has not created the repo and only has access to the repo due to the team membership is trying to access the repo page, he will be redirected to the admin-page. The workaround is to add the user explicitly (he can do this himself) as an admin on the repo.