This might answer some of the questions that have been raised concerning FR24 data:
We acquired a signal from the aircraft shortly after takeoff and tracked it until 04:13:22 UTC. At the time of last contact we were receiving a signal from the aircraft to three of our receivers, all of which stopped receiving data from the aircraft at the same time.
Source:
Crash of Metrojet Flight 7K9268 | Flightradar24 Blog