Hi!
Attached is the 3D roughing code and the profile of the machine I was running it on.
X going left moves and Z going up moves below Y=0 are being ignored by UCCNC.
I practically ripped the machine apart trying to find the root cause. Changed cables. Disconnected everything except Z axis stepper. It still happens.
Found out that disabling the spindle relay control makes the problem go away. BoB is now suspect Swapped in a BoB with only Z step/dir connected. Still happens.
Changed the Z step/dir IO pins. Still happens.
Then I found a suitable workaround: change Y and B step pins to active low.