This is exactly what I heard today morning when I called- honestly the poor agent sounded so tired, but what she explained to me was, that its not possible to take the test without an email invitation. The email invitation is usually only sent after an internal system check has been reached, so if other people have taken the test, it would be because their test was issued and perhaps in their junk email and therefore they are allowed to do it- they just did not see the email. If theres no email at all, then they will have to have their cases manually reassessed by an agent to see how they were allowed to complete a test when the system did not request it, but most likely if the person passed the test, it would count as test taken and passed when investigated.
They did say that the system has been in error for citizenship tests and ceremonies so to wait for emails or updates on the tracker. New invites and windows will be issued- she did not say when.
