Auto bed leveling issue

Hi, I'm working on a homemade TAZ.

I applied the 1013 mod for auto bed leveling : [forum.lulzbot.com] .

I'm encountering some difficulties having this mod working on the firmware part (I think).

All is well wired and working, motors, endstops... all checked manually via pronterface.

For the moment I'm trying to check the feature manually.
Executing this is working fine :
G28 X0 Y0; home X and Y axes
G1 X276 F11520; go to probe deployment position
G1 X288 F350; deploy probe
G1 X250 F11520; go to safe place
G28 Z0; Home Z axes


But when I execute G29, it is not executing the process as expected.
Instead of leveling up in Z going to a point, leveling, and etc for each point, I have no Z move and no Y move.
The carriage is moving along X axis only, and the process ends giving 0 corrections as expected with auto-level (and I know there should be, the center is a bit "higher" than the side because of the way my plate is pinched).

Any idea where it could come from ?
Any orientation welcome .

Regards

Note : I paid attention executing M502 / M500 in order to have my config settings well applied, but nothing better.
Note 2 : config joined in case someone would see something in it.