Z-axis does not home to limit switch

I am trying to build my own CNC router using arduino Uno + CNC Shield and running grbl 1.1f. Everything works as expected, X and Y axis home correctly, but the Z axis for some reason does not home to a limit switch. It does move, about 4 mm, and then the X and Y axis home. The position does get reset to the correct value, but the Z axis just is not in the right place. All limit switches are wired correctly and work correctly. I am able to jog all the axis around without issues. I have tried all kinds of setting combinations but nothing fixes the problem. I also tried pressing the Z limit switch manually as the Z axis was "homing" and that just sent the controller into an error and I am forced to rehome, which is really weird because as far as I understand it, the controller should be looking to hit the limit switch. So this makes me think there is some setting I just was not able to find anywhere.

Thanks for any advice.

Just in case, here are my grbl settings:
$0=10
$1=25
$2=0
$3=2
$4=0
$5=1
$6=0
$10=1
$11=0.010
$12=0.002
$13=0
$20=1
$21=0
$22=1
$23=4
$24=80.000
$25=1000.000
$26=15
$27=3.000
$30=1000
$31=0
$32=0
$100=25.000
$101=25.000
$102=25.000
$110=2000.000
$111=2000.000
$112=400.000
$120=10.000
$121=10.000
$122=10.000
$130=330.000
$131=295.000
$132=110.000

 

****, that actually solved the problem. Never experienced EMI causing troubles with digital inputs, anyway, thanks

 

Literally just placed the stepper motor wires and limit switch wires further away from each other.