Duet ethernet homing failure

I have setup a printer Pursa I3 style using duet Ethernet board. I have endstop switch normally closed "bare switches" on X,Y,Z min. Active High signals for all three. All travels have been verified for speed and distance, and no electrical nor mechanical issues exist. However printer will not home any axis properly. The printer will slowly move back and forth a few mm than post error on web interface stating homing failed. This happens with a single axis and home all. Also happens using pronterface and repieter host. M11 S0 is listed in config.g to ensure debug doesn't interfere. All switch states and in good standing, confirmed via led status and machine properties page. Switch state behave as intended when manual manipulated. A G91 than G1 S1 X100 command will bring X 100mm toward the switch and printer will stop at switch using this method. However a G28 command for the same axis will result in 1 of 3 failures. 1st printer won't get past the shakes. Second printer strikes switch, fails to stop. Third printer homes wrong direction. All 3 versions of failure occur randomly with no alteration of any files and no other changes including hardware, wiring. This issue has persisted for 2 weeks with no answer in sight. Firmware has been erased and rewritten to board. Config files download a zip direct for David the co/author of this system. He doesn't seem to understand why failure persists. He has reviewed all me files and machine description. He has stated there is nothing about the machine that would cause this issue. I will post my config file and homing x y z and homeall.g for review. I change anyone who is up to the task to help me with this issue..

; Configuration file for Duet Ethernet (firmware version 1.17 to 1.19)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Sat Nov 25 2017 12:15:39 GMT-0500 (Eastern Standard Time)

; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M555 P1 ; Set firmware compatibility to look like RepRapFirmare
G31 X-40 Y25 Z1.5 P25
M208 X0 Y0 Z0 S1 ; Set axis minima
M208 X295 Y295 Z207 ; Set axis maxima


; Endstops
M574 X1 Y1 Z1 S1 ; Set active low endstops
M558 P5 X0 Y0 Z1 H5 F100 T2000 ; Set Z probe type to switch, the axes for which it is used and the dive height + speeds
G31 P600 X0 Y0 Z2.5 ; Set Z probe trigger value, offset and trigger height
M557 X40:210 Y40:240 S20 ; Define mesh grid

; Drives
M569 P5 S1 R1 T2 ; Drive 0 goes forwards
M569 P6 S1 R1 T2 ; Drive 1 goes forwards
M569 P7 S1 R1 T2 ; Drive 2 goes forwards
M569 P8 S1 R0 T2 ; Drive 3 goes forwards
M569 P9 S1 R0 T2 ; Drive 4 goes forwards
M569 P10 S1 R0 T2 ; Drive 5 goes forwards
M584 X5 Y6 Z7 E8:9:10 ; Apply custom drive mapping
M350 X16 Y16 Z16 E16:16:16 I0 ; Configure microstepping with interpolation
M92 X100 Y100 Z3200 E80:80:80 ; Set steps per mm
M566 X900 Y900 Z12 E120:120:120 ; Set maximum instantaneous speed changes (mm/min)
M203 X10000 Y10000 Z280 E1200:1200:1200 ; Set maximum speeds (mm/min)
M201 X600 Y600 Z250 E250:250:250 ; Set accelerations (mm/s^2)
;M906 X800 Y800 Z800 E800:800:800 ; Set motor currents (mA)
;M84 S0 ; Disable motor idle current reduction

; Heaters
M307 H7 A-1 C-1 D-1 ;disable heater 6 to free up for servo signal
M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
;M143 H0 S60 ; Set temperature limit for heater 0 to 60C
M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S280 ; Set temperature limit for heater 1 to 280C

; Tools
M563 P0 D0:1:2 H1 ; Define tool 0
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C
M568 P0 S1 ; Enable mixing for tool 0
M567 P0 E0.33:0.33:0.34 ; Set mixing ratios for tool 0

; Network
M550 PMy printer ; Set machine name
M540 PBE:EFE:AD:FE:ED ; Set MAC address
M552 P192.168.2.9 S1 ; Enable network and set IP address
M553 P255.255.255.0 ; Set netmask
M554 P192.168.1.254 ; Set gateway
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet

; Fans
M106 P0 S1 I0 F500 H1 T45 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P1 S1 I0 F500 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S1 I0 F500 H1 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Custom settings are not configured

; Miscellaneous
T0 ; Select first tool

; homex.g
; called to home the X axis
;
; generated by RepRapFirmware Configuration Tool on Sat Nov 25 2017 12:15:39 GMT-0500 (Eastern Standard Time)

G91 ;relative moves
G1 z5 F3000 ; move head up
G1 X-310 F1500 S1 ;move -310 mm stop at switch
G1 X5 F1000 : move back slowly
G1 X-310 F360 S1 ;Move -310 stop at switch
G92 X0 ;tell firmware where we are
G90 ;absolute move
G0 X140 Z2.5 F1500 ; move to X to center z up


; homey.g
; called to home the Y axis
;
; generated by RepRapFirmware Configuration Tool on Sat Nov 25 2017 12:15:39 GMT-0500 (Eastern Standard Time)

; Lift Z relative to current position
G91
G1 Z5 F3000 ;move head up
G1 Y-310 F1800 S1 ;move -310 neg dir stop at switch
G1 Y5 F1500 ;move back 5mm pos
G1 Y-310 F560 S1 ;move -310 allowance stop at switch
G92 Y0 ;tell firmware where we are
G90 ;absolute moves
G0 Y140 Z2.5 F1500 ; mo y to center z2.5 up


; homez.g
; called to home the Z axis

G91 ;relative moves
G1 z5 F200 ;raise head 5mm to ensure it above trigger height
G90 ;back to absolute moves this might be wrong G91
G1 X140 Y140 F2000 ;put probe at bed center
G91 ; relative moves
G1 Z-210 S1 F100 ; move down until triggered height
G90 ;back to absolute
G92 Z0.3



; homeX,Y.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool on Sat Nov 25 2017 12:15:39 GMT-0500 (Eastern Standard Time)

; Relative positioning
G91
G1 Z5 F3000 ;lift Z 5mm
G1 X-310 y-310 F1500 S1 ;relative move to x,y -310mm neg dir stop at switch
G1 X5 Y5 F1000 ;relative back off switch 5mm pos dir
G1 X-10 Y-10 F360 S1 ;relative move x,y -310mm alliance neg stop at switch slowly
G90 ;absolute moves
G1 X140 Y140 F2000 ; put probe center of bed
G30 ;lower probe set height
G0 X140 Y140 Z2.5 F1500 ; absolute move to bed center first probe position

Answered on the Duet3D forum.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].