Southwest Has Taken The 737 Max Off Its Schedule Through August

The airline has extended the removal of the 737 Max from its schedule until August 10th due to uncertainty about the aircraft's return to service. This decision aims to minimize last-minute cancellations and disruptions. Southwest will cut 371 weekday flights from its January schedule. Boeing anticipates the 737 Max will be operational by mid-2020. The aircraft was grounded globally after two fatal crashes, with the flight control system partly blamed.

What were the circumstances that led to the grounding of the 737 Max aircraft?

What aspect of the Krafts flight control system is believed to be partially responsible for the crashes?