Some things to consider. Make sure that the switch is in a position where it can hit it and move back
enough to open. Make sure the switch lever is actually hitting the bumper washer too. Some folks have said theirs didn’t. I had to put in a larger washer to compensate on mine. You could also have a bad switch, so if you have a multimeter…you may want to check it. Here are all the grbl settings.
$22 is homing enabled/disabled.
How to change one is in the link below.
GRBL_Settings_Pocket_Guide_Rev_B.pdf (diymachining.com)
see the 3rd post here
Calibrating my X-carve 1000 - X-Carve - Inventables Community Forum