I use Apple Business Manager to install apps on my office iPads and to track them. I am a beta tester for a company that pushes new versions of their software through TestFlight. These iPads are logged into managed apple accounts [apple IDs] under my Apple Business Manager account. When I attempt to open TestFlight, I receive a message "TestFlight is currently unavailable, try again later." If I logout and sign in an iPad under a consumer Apple Account, TestFlight works properly. I however, want to use these iPads under my apple business account.
TestFlight is Unavailable
Sorry for the delay, are you still having that issue with TestFlight? Is now currently available?
Albert Pascual Worldwide Developer Relations.
Unfortunately yes. I am hearing that it is related to managed [federated] Apple ID accounts. Even though it is my domain and I control these accounts, it is blocked on the apple side. Developers say it is not a restriction on their end. Unfortunately the only workaround is to logout of the managed Apple ID account, login to a consumer Apple ID account, download the software I need through TestFlight, then logout and log back in with the managed Apple ID which is quite a bit of work.