Expert flyer has been all wonky lately with CX. Was flying SFO-HKG-SFO in PE. Showed almost full on way out then around a day left 9+ open in each cabin. I verified I could at least book 6 seats in any cabin, but arriving at airport staff said it was fully booked (while they were still selling tickets online). Same thing on way back. Return ended up overbooked in Y and PE and my wife and I got upgraded to J. Walked back to PE to see at least 2 open seats left. Must have had some last minute no shows or something strange was going on with seat management. At least we got to keep the upgrade :-)