Still very odd. SpaceX released a statement saying the Falcon 9 did the mission 100% correctly. We also have citizen footage of fairing seperation and second stage de-orbit confirming they happened at the correct times.
So it can be assumed a fact that ZUMA did reach orbit and the news stating otherwise is wrong. Maybe the sources are wrong or maybe the writers misunderstood. Either way it just makes things more confusing.
Edt: I'm moving into team fake. If the sat was still on stage 2, it would have increased the weight needed for the deorbit burn. So since people saw stage 2 pump out leftover fuel after the burn, we'd know ZUMA wasn't there or was super light. Also this leaked super fast for being something so secret.
Option 1: ZUMA reached orbit but failed to seperate from the second stage. Instead of trying to save ZUMA and look into options, the gov decided within 2 hours to procede with the planned deorbit of 2nd stage and make sure ZUMA landed in the ocean.
Option 2: ZUMA did seperate and then its thrusters failed, or it had another problem and was deorbited on purpose.
Option 3: the leaked info is wrong and the sat is still in space or it wasn't a sat and did its mission.