Homing Y sometimes triggers before endstop

[reuel]

Hi, I've got a cartesian printer that I recently moved from a Duet 2 Maestro board to a Duet 3 Mini. It prints well right now but sometimes when I home (not always), the Y axis stops partway, as if the mechanical endstop were triggered. The point where it stops can vary, sometimes shortly after starting the move, sometimes near the middle, and sometimes close to the endstop. I suspected that it had something to do with sensorless homing or stall detection but I have experimented with numerous settings to no avail. My endstops are also not configured for sensorless homing so I'm baffled. Any ideas what could be causing this?

Here's my config:

; General
G90 ; absolute coordinates
M83 ; relative extruder moves

; Accessories
M575 P1 S0 B57600 ; configure PanelDue support

; Network
M552 S1 ; configure WiFi adapter
M586 P0 S1 ; configure HTTP

; Smart Drivers
M569 P0.0 S0 D2 ; driver 0.0 goes forwards (extruder 0)
M569 P0.1 S0 D2 ; driver 0.1 goes backwards (X axis)
M569 P0.2 S1 D2 ; driver 0.2 goes forwards (Y axis)
M569 P0.3 S0 D2 ; driver 0.3 goes backwards (Z axis)
M569 P0.4 S0 D2 ; driver 0.4 goes backwards (Z axis)

; Motor Idle Current Reduction
M906 I30 ; set motor current idle factor
M84 S30 ; set motor current idle timeout

; Axes
M584 X0.1 Y0.2 Z0.3:0.4 ; set axis mapping
M350 X32 Y32 Z32 I1 ; configure microstepping with interpolation
M906 X1360 Y1360 Z1360 ; set axis driver currents
M92 X201 Y201 Z790 S32 ; configure steps per mm
M671 X-44:371 Y0:0 S2.0 ; Position of leadscrew/bed pivot point at left and right of X axis, with max deviation of 1 mm. For auto leveling of the X gantry.
M208 X0:300 Y-15:295 Z0:180 ; set minimum and maximum axis limits
M566 X1200 Y1200 Z12 ; set maximum instantaneous speed changes (mm/min) (jerk)
M203 X12000 Y12000 Z360 ; set maximum speeds (mm/min)
M201 X2000 Y2000 Z15 ; set accelerations (mm/s^2)
M915 X Y Z S100 F1 R0 ; Configure stallGuard to threshold 100, unfiltered reading per stop and log event (tried to see if a high threshold would overcome this issue)


; Extruders
M584 E0.0 ; set extruder mapping
M350 E32 I0 ; configure microstepping without interpolation
M906 E850 ; set extruder driver currents
M92 E1380 ; configure steps per mm
M566 E120 ; set maximum instantaneous speed changes (mm/min)
M203 E3600 ; set maximum speeds (mm/min)
M201 E3000 ; set accelerations (mm/s^2)

; Kinematics
M669 K0 ; configure Cartesian kinematics

; Probes
M558 K0 P9 C"io3.in" H5 F120 T6000 ; configure BLTouch probe via slot #0
G31 P500 X-24 Y-27 Z2.886 ; set Z probe trigger value, offset and trigger height. Increase Z to bring hotend closer to bed.
M950 S0 C"io3.out" ; create servo #0 for BLtouch

; Endstops
M574 X1 P"!io1.in" S1 ; configure X axis endstop
M574 Y1 P"!io2.in" S1 ; configure Y axis endstop
M574 Z1 S2 ; configure Z axis endstop

; Mesh Bed Compensation
M557 X20:280 Y20:280 S40:40 ; define grid for mesh bed compensation

; Sensors
M308 S0 P"temp0" Y"thermistor" A"Heated Bed" T100000 B4092 ; configure sensor #0
M308 S1 P"temp1" Y"thermistor" A"Nozzle" T100000 B4658 C6.5338987554e-8 ; configure sensor #1

; Heaters
M950 H0 C"out0" T0 ; create heater #0
M143 H0 P0 T0 C0 S100 A0 ; configure heater monitor #0 for heater #0
M307 H0 R0.792 C487.1 D2.18 S1.00 B1 V24.3		; Set the PID for the bed heater
;M307 H0 R2.43 D5.5 E1.35 K0.56 B0 ; configure model of heater #0

M950 H1 C"out1" T1 ; create heater #1
M143 H1 P0 T1 C0 S300 A0 ; configure heater monitor #0 for heater #1
M307 H1 R4.106 K0.444:0.000 D4.21 E1.35 S1.00 B0 V24.0 ; configure model of heater #1

; Heated beds
M140 P0 H0 ; configure heated bed #0

; Fans
M950 F0 C"out5" ; create fan #1
M106 P0 S0 L0 X1 B0.1 ; configure fan #1

M950 F1 C"out3+out3.tach" ; create fan #0
M106 P1 X0.6 B0.1 H1 T45 ; configure fan #0
;M106 P0 S0 L0 X0.5 B0.1 H1 T45 ; configure fan #0

; Tools
M563 P0 D0 H1 F0 ; create tool #0
M568 P0 R0 S0 ; set initial tool #0 active and standby temperatures to 0C

; Miscellaneous
M591 D0 P1 C"io4.in" S1 ; Enable filament sensor, simple sensor (high signal when filament present) connected to IO_4 for drive 0
;M572 D0 S0.06; Set pressure advance

M501 ; load saved parameters from non-volatile memory
T0 ; select first tool

And here's my Y homing file:

G91                ; relative mode
G1 Z4 F200 H2      ; raise head to avoid dragging nozzle over the bed
G1 Y-340 F3000 H1  ; move up to 340mm in the -Y direction, stopping if the homing switch is triggered
G1 Y4 F600         ; move slowly 4mm in the +Y direction
G1 Y-15 F300 H1         ; move slowly 15mm in the -Y direction, stopping at the homing switch
G1 Z-4 F200 H2     ; lower the head again
G90                ; back to absolute mode

Thanks for your help.

[Phaedrux]

It's likely that your end stop wiring is picking up interference.

https://docs.duet3d.com/en/User_manual/Connecting_hardware/Sensors_endstops#interference