You are homing to z max? Make sure bead coating is set 0 as this changes result when homing.
S2 computes new height by adding the difference between old and new z from z probing as this is the change measured.
Where z probe triggers /high/low) is not important if configured correctly. As long as M119 shows L when not triggered and H when triggered it is used correctly.
To understand how to change always think when you trigger you are at z probe height for z while it assumes a different height from z used for homing. The difference is the error which gets corrected. So higher z probe height means it thinks it has a higher z at that point so it needs to increase z height so next homing is then really at that z height.
