It is foolish to rely on FR24, the sytem works by collecting data over the internet from amatuer ADSB receivers owned by enthusiasts and joining the dots. There are plenty of these stations in well populated areas but the chances of any reliable receiver data in the middle of an enormous desert are a tad slim.
@TAG
While the second part of your comment is correct, the Sinai is far from an "enormous desert". While FR24 appears to be blocked in Egypt, Beer Sheeva/Eilat/Aqaba are all within 100nm of LKP, and Tel Aviv is under 200nm, the effective range of such amateur ADS-B receivers. FR24 data over the Sinai is likely to be reasonably valid.
If you look at FR24 there are several a/c over the Sinai being tracked in real time with good data right now, along the same routing as was taken by the accident flight.