Need to discard the first probe - help me find the root cause

[Sineos]

@terra

As best as I can tell, it’s largely an issue with belted Z printers, particularly when the reduction gears are also run with belts. Increasing tension there improved, but did not fix the behavior. I hear switching to worm Z drives fixes the issue, which I will be doing shortly

One of my printers has a lead-screw Z-axis and I’m seeing this as well, despite anti-backlash nut and carefully rigging it.