Here is a short movie with homing routine on The Thing printer. First: Z axis homing doesn’t work after X and Y. Second: At the end strange behavior of the stepper during only Z axis homing. Today I have no idea what is causing this.
Sounds like maybe the homing speeds are set too high for Z. I think mine are at 0.007 and backoff speed is 0.01
Also, if you move z down first then try and home does it attempt to home it? Maybe you don’t have a backoff distance and if it is already hitting the end stop it will not hom
I know that sound all too well. It is a z stepper motor movement speed that is too fast. Just slow it down til it moves as expected.
Thank you so much for help! I changed the speed at 0.005 and now works as it should 
Just a small efficiency thing, but I think you can home x and y simultaneously. Does that not work?
@Elias_Bakken Yes, homing the X and Y running simultaneously. Now the homing Z also works. Only wonder how to do the homing of all axes in one cycle like on your video. But I still recognize the printer to work with Replicape and I have to learn more.
@Daniel_Kusz does issuing a G28 with no parameters home all or does it still use a config option for the order?
A clean G28 should home all axes that have an end stop.