The offset should be set to negative numbers. 1.9 is very high.
Sometimes the printer starts to print in the air because the stepper motors has timed out. The printer does not know the location and starts to print in the air. You can see that on your LCD, if the locations has question marks, the printer has lost the location and needs G28 to fint it again.
Set DEFAULT_STEPPER_DEACTIVE_TIME to 0 in Configuration_adv.h and it will never time out and keep the steppers energized.