I found this article


https://github.com/MarlinFirmware/Marlin/issues/1682

They were discussing that somewhere in marlin_main.cpp there was a line of code that offset the z axis by some amount, I dont know exactly why.

They said it was around line 1103 in the cpp.

Someone set Z_Raise_Before_Probing to zero in the cpp, to keep the head from moving up before it initiates a G29. Could this be the source of the z offset ghost?