Hello,
This can be a normal config if you use different servo-drives. If they are all the same check your wiring. Especially the grounding.?
Are there any settings (dipswitches?) on the drives? doublecheck those.
Do the problems also occur when you use MDI?
try typing directly in the MDI line "G1 Z(some value) F1000"
see if it works?
Kris.