I'm trying to get UBL working with a BLTouch probe. I have the probe working, and homing works. I can also run the UBL mesh probe and get what looks like reasonable results. However, when it's active, Z0 is actually more like Z-4. I could edit the mesh, and that might work, but it seems too consistent to be a bug and more likely something I'm doing wrong. I have attached the config files and logs of some testing. I determined the Z nozzle/probe offset by homing, then moving down till paper drags on the nozzle. Then using M114 to adjust the offest. The offset consistently gives good Z0 with leveling disabled after a G28. M502/M500 before every test.
Hardware is an older Lulzbot mini v1, mini Rambo board, with the bltouch wired per this post. [
reprap.org]
I tried the 2.0.x and bugfix-2.0.x branches, they had similar results.