Attention is centring on the planes anti-stalling system, which was found to be responsible for the previous Lion Airlines crash.
// Early data from the [Lion Airlines] doomed plane's flight recorder suggests that for much of its 11-minute flight on October 29, the pilots were struggling with the craft's Maneuvering Characteristics Augmentation System (MCAS).
This is a computer system designed to prevent the nose of the Boeing 737-Max from pulling too far up and putting the plane into a stall when under manual control. It has nothing to do with the airplane's autopilot.
According to an early analysis of the crash, based on the partial release of flight data, the MCAS appeared to have mistakenly sensed a looming stall and tried to force the plane's nose down. The pilots responded by pulling the plane's nose up to compensate, only to have the MCAS system force the nose back down again.
In effect, they were wrestling with software and hardware inadvertently trying to kill them. It is thought an angle-of-attack sensor passed bad readings to the automatic MCAS, which downed the plane as a result. //
https://www.theregister.co.uk/2018/11/27/boeing_737_max_mcas_lion_air/