Your ini start up line has ag20 in it, change to g21.
Homing sequence is set in the ini, read the lcnc docs for how to configure homing settings correctly. All homing is stock linuxcnc motion. Go to home is for the go to home button. You can edit it to suit your needs, but has nothing to do with homing. All homing settings are in the ini under each of the axis sections.
