With the use of a Bltouch (automatic elevating), It would be imperative to perform an homing XY, before being able to launch a homing Z, because if the bed was out at maximum manually the bltouch can not be in conatct with the bed , and it is the nozzle that comes into contact with the plate until the blocking of the motor Z, and this causes a shift in the screws Z
I have moved this post to General since it doesn't appear that you are seeking help (just providing information for others who might have a Bltouch as well).