Strange.
All this time I've been experiencing the airport in the dark on arrival, but if I spawn at the airport at night, all the lights are on. Just the other day I did a flight arriving into KORD, and all the lights were on. First time I've seen it lit up. Looks amazing.
So now thinking what could that have been?
Hard to track that down, there's been many updates lately. I'm still on 4.5. Just glad it's working.