For approximately one week, we have been unable to send TestFlight internal testing invitations.
Invited users appear with the status "Invited", but no invitation date is displayed, and no emails are received.
We have already tried recreating groups, resending invitations, using Safari, uploading different builds, and inviting users individually.
All email addresses, user roles, and account requirements are correct.
Interestingly, we also tested the same process using another developer's App Store Connect account, and invitations were delivered successfully. The issue only occurs with our account.