DevOps is aiming to make phabricator self-service by the end of this month.
To enable that, there'll be some changes (ongoing) in phabricator access control, mainly:
Expected problem: currently, there are many users that don't belong to any team. This may result in inacessible differential/repositories/reviewers/etc.
Solution: If you're experiencing this, the first thing to try is asking your team lead to add you to your team in phabricator. If the problem persists, kindly ask us in #devops-channel