Z motors only working manual, do not home correctly
Jogging the Z axis may be a sequence of very short moves, happening relatively slowly.  

Homing may be a longer, faster move.  The homing move would depend more heavily on the maximum velocity, maximum acceleration, and jerk parameters.  If there are too high the z axis won't operate properly since the motors will attempt to move faster than is supported by the torque, and the rotating magnetic field will lose control of the permanent magnet rotor.

To fix this, find how the motion limit parameters are controlled for your software, and reduce them all by a factor of 50. It should work, although perhaps too slowly.

I would also reduce the current setting.  Microstepping motors doesn't work when the magnetic field is driven to saturation.