I’m seeing the same issue, and unfortunately the workaround is no longer reliable for me either. I have an existing external testing group with a valid build assigned to it. Existing testers can install and use the build normally. When I add a new tester to the same group, that tester shows “No Builds Available”, even though the build is still active and assigned to the group. Initially, removing the build from the group and adding the exact same build again made it available to the new tester. However, this workaround has now stopped working as well. Re-adding the build also sends duplicate notification emails to existing testers, so even when it worked it was not a practical solution. This looks like a TestFlight/App Store Connect issue with build access not being propagated correctly to newly added external testers. Is anyone aware of a current workaround, or has Apple acknowledged this issue?