Thatswhy I was already asking whether the 270 MHz are correct or not. Unfortunately I was too lazy googling the answer and I’m running the PRO with I think 500 MHz.
This was a very long story that again showed the complexity of that whole business.
As we often do have such topics maybe @Sineos can somehow take this into the basic troubleshooting steps or highlight it at another kb article?!
@limefrog happy homing and printing! 
My Z homing works as well and even Z_Tilt works with the triple Z upgrade. Just have to get the Z motors much quieter and fire up the new bed once the PE cable is installed.