My bed is always at full temp before I probe and the hotend gets there as it is probing but that would make no difference with this AFTER I initially did the 1.95 (both were at full temp for that). Remember 2.0 was my first with a paper test then 1.98 after it did a layer but 1.95 was a perfect layer.

My point was that I have been doing just fine until today when it magically shifted by .02mm. Having to do the m114 jog around as I first did but each time would make me throw the printer out the window. The nozzle didn't shift upward on its own so I am stumped.

As far as the m851 goes I am not understanding how that would solve this particular issue where it was all set perfectly but one day decides to change.