I had this same problem. I was on the queue for more than 2 hours. Eventually, I was told that my session expired. I had to withdraw the exam. I called ACCA and they said I had to wait till September. The queue started with 566 persons around 4.50AM EDT and only got to my turn around 6:45AM EDT. I was asked to relaunch VUE. I was 1st in line but the Proctor never showed up for almost 1 hour, till I got an error and the session became invalid.