All 737 MAX have two sensors. The Lion Air flight had sensors disagreeing by 20° right from the start. This made the stick shaker go off on one side right after

All 737 MAX have two sensors. The Lion Air flight had sensors disagreeing by 20° right from the start. This made the stick shaker go off on one side right after departure (throughout the entire flight) and led to a multitude of other alarms (altitude disagree, unreliable airspeed).