New to this forum; but use FltAware a lot. Tonight tracking DAL#8581 from JFK to CDG but all numbers/times and DeGaulle Airprt code changed i.e. the flt. was AirFrance 007 but 007 didn’t show up either???plus when I found the flt. it was 2.5 hrs.late leaving. Flight Aware was slow to clarify any of this, not my PC!!! Could not glean much information as to when ActualTimeDepart would be; I spent untold hours on this. I’m very disappointed in Flight Aware. Shame on You. 
CDG = LFPG
I believe the flight you were trying to track was this one:
flightaware.com/live/flight/AFR7 … /KJFK/LFPG
Often airlines will use equipment belonging to another airline and “code share” their flights. Someone else will be more than happy to expound on this if you are interested.
In this case, the flight you should have been looking for was Air France 007, AFR7.
Now to address the issue of airport codes changing - they don’t. Monsieur Wiki has a chapter which simplifies the differences between IATA & ICAO codes. en.wikipedia.org/wiki/Internatio … rport_code
Quote fron reference: The ICAO codes are used by air traffic control and airline operations such as flight planning. They are not the same as the IATA codes encountered by the general public, which are used for airline timetables, reservations, and baggage handling.
Also thought new FAA rules state a plane sitting on tarmac over 2hrs. has to return to the terminal. Scheduled departure was 7:05p.m.EST Actual departure was 9:30p.m. EST.
[cough] 3 hours [/cough]
The flight left late, but the airline didn’t provide an updated flightplan for some time so we had no way to know when they planned to depart. As soon as we had the updated flightplan, we posted the new departure time on our site.
Tarmac rule only applies to domestic flights (and possibly only to domestic carriers, I’m fuzzy on that part).