At 1st instance I would say “on the ground” aircraft. For the tests I have been running through, I was spawning at KJFK trying to understand the traffic displayed on the world map vs traffic on the EFB vs traffic once spawned.
Approaching & and taking off (once airborne) traffic seems to match what I was seeing on FlightAware. Example at KJFK, JBU996 landing RWY 31R:
Maybe some discrepancies can exist with airborne traffic. If you have some evidences feel free to post them here, I can always adjust the title/description if needed.
I’ve noticed this today as well.
There are discrepancies between the AI traffic displayed on the free flight start screen, the EFB, and the traffic injected into the simulator.
Although the start screen and the EFB show a large amount of traffic, once in flight, the same number of aircraft are not injected, either on the ground and in the air.
Furthermore, some aircraft appear and disappear randomly.
Sometimes they do so when you approach them, other times they appear and disappear randomly. It’s a bit chaotic.
Between this and the synchronization problems in multiplayer mode, reported by many users in other posts, features that should distinguish this simulator for its ease of use become problems and sources of criticism, completely ruining the experience.