Issue with G38.5

Hi new here.

Using linuxcnc 2.8.4-1 and having issues with g38.5 commands.  The probe I am using is a magnetic encoder on a rail and spring system to measure distance.  My hal is setup so that a displacement of >0.005in will trigger the probe input.  The gcode starts with a g38.3 to probe the piece to get its location.  Then using g38.5 command to determine the edge of a part by moving in z until the probe falls off.  I've had issues with "probe tripped during non probe move" so I am controlling the activation of the probe input signal with a digital io pin.  I am still getting "probe tripped during non probe move" errors and confused as to why it is still happening.  

Hal config:
#Negate Encoder Position
setp mult2.2.in0 -1.0                    
setp comp.0.in0 0.005                   # Threshold value for encoder
net enable-probe    <=    motion.digital-out-03    =>    and2.1.in1

# Encoder position and comparator
net negated-encoder-out <= mult2.2.out
net negated-encoder-out comp.0.in1       # Connect to comparator input
net encoder-threshold-met    <=    comp.0.out   => and2.1.in0

# AND logic to trigger only during probing motion
net probe-trigger and2.1.out motion.probe-input

Gcode:

M64 P3    (enable probing) 
G38.3 F15 Y1.6  (probe vertically into the part)
G38.5 Z4 F25 (drag off edge) 
M65 P3    (disable probing) 
G4 P0.1 (dwell to make sure the signal was sent to disable probing)
 

Awesome thank you!