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.