@Lasko said in Z-Homing via endstops vs. Mesh Bed Compensation:

M671 X--xxx,xx:xx,xx:xxx,xx ... is invalid M671 X-xxx.xx:xx.xx:xxx.xx ... is valid

So no commata or "-" between X/Y and the values!

Just to be sure you understand a hyphen indicates a negative value.

So the "valid" example has the first location as negative.

Frederick