I think the one a few years ago was slightly different. If I recall correctly there were two severs (IPs?) and all traffic was being directed to one of them. Someone figured out if you hit the second one you got straight in because it was under-utilised. I think they fixed it about 2/3s the way through that sale.
Todays seems different. It’s as if there is something throttling getting onto a booking server. But if you can direct straight to it you get straight in.
Someone with better tech knowledge can probably explain both a lot better.