I have the following setup:

CoreXY, 3 axis Z with IR bed probe. X and Y use sensor less homing, Y needs to be done before X

BIGTREE_SKR_PRO 1.1

TMC-2130s with diag pins cut on Z1,Z2,Z3

Marlin: 2.0.9.1

Config diff: [git.techdroid.com]

Video showing the issue: [youtu.be] (please ignore the fact that the probe is not at optimal height compare to the nozzle right now. The red light flashing is the trigger indicator on the IR sensor board)

When I trigger G28 Y X I can home XY fine. Then I can also home Z with G28 Z correctly. However if I do just a G28, XY will home but Z will trigger right as it tries to raise the bed. I have the same issue when I replace the G28 in my start GCODE with G28 Y X and G28 Z. However if I do those by hand (via display or console) I have no issue.

Does anyone have any ideas what could be the issue? I am out of things to try. What is the difference between G28 and G28 Z? Could it be RF noise? why however does G28 Z work?

Edited 4 time(s). Last edit at 08/01/2021 10:04AM by sschueller.