In mid-to-late 2019, Creality upgraded the base Ender-5 leadscrew to the same one used on the Ender-5 Pro which prevents the bed from dropping once power is cut.
If your machine shipped with the upgraded leadscrew (or if your prints are 1/2 as tall as they should be), change your Z steps from 400
to 800
in Configuration.h
:
Before:
DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 400, 93 }
After:
DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 800, 93 }
Or by sending M92 Z800
followed by M500
after updating your firmware.