[3.6.0-rc2] Error: G30: Z probe readings not consistent

[caviara]

Hi team,

I came across a small issue with FW 3.6.0-rc2, as following:
When i try to home Z (using IR probe on CoreXY), after the initial probe, and when the bed is moving down (every time) i have slight movement, about 1mm, of the carriage in X+ direction, which (i believe) leads to the following error in console (and on the PanelDue):

G28 Z
Error: G30: Z probe readings not consistent
Error: Z probe readings not consistent
 

This movement in X+ is valid on every single probe made with G30, i mean - two probes = two movements.
This problem initially appeared after yesterday i upgraded to 3.6.0-rc2 from the previously installed 3.6.0-beta2.
Today in order to get some parts printed i downgraded to 3.5.4 "(stable one) and problem disappeared.
After this initial print i got back to the 3.6.0-rc2, and behavior is present.

My setup is as follows:
CoreXY on Duet3 6CH (V1.0 as i remember), with IR probe.

Here are the config files:
config.g
config-override.g
homeall.g
homez.g
(sorry for all the mess in those, still have not found time to clean them out )

and here is the result from M122:

4/18/2025, 8:37:07 PM 	M122
=== Diagnostics ===
RepRapFirmware for Duet 3 MB6HC version 3.6.0-rc.2 (2025-03-31 12:17:13) running on Duet 3 MB6HC v1.0 or earlier (standalone mode)
Board ID: 08DJM-956L2-G43S4-6JKD2-3SD6R-1U56F
Used output buffers: 1 of 40 (34 max)
=== RTOS ===
Static ram: 137420
Dynamic ram: 127860 of which 448 recycled
Never used RAM 78088, free system stack 140 words
Tasks: NETWORK(1,ready,28.8%,180) ETHERNET(5,nWait 7,0.1%,322) HEAT(3,nWait 6,0.0%,329) Move(4,nWait 6,0.0%,242) TMC(4,nWait 6,3.2%,341) CanReceiv(6,nWait 1,0.0%,939) CanSender(5,nWait 7,0.0%,334) CanClock(7,delaying,0.0%,338) MAIN(1,running,67.8%,103) IDLE(0,ready,0.0%,29) USBD(3,blocked,0.0%,149), total 100.0%
Owned mutexes:
=== Platform ===
Last reset 00:13:09 ago, cause: software
Last software reset at 2025-04-18 20:23, reason: User, Gcodes spinning, available RAM 78328, slot 0
Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0043c000 BFAR 0x00000000 SP 0x00000000 Task MAIN Freestk 0 n/a
=== Storage ===
Free file entries: 20
SD card 0 detected, interface speed: 25.0MBytes/sec
SD card longest read time 3.9ms, write time 0.0ms, max retries 0
=== Move ===
Segments created 10, maxWait 140309ms, bed comp in use: none, height map offset 0.000, hiccups added 0/0 (0.00/0.00ms), max steps late 0, ebfmin 0.00, ebfmax 0.00
Pos req/act/dcf: 23781.00/23781/0.00 321.00/321/0.00 2070.00/2070/0.00
Next step interrupt due in 247 ticks, disabled
Driver 0: standstill, SG min 0, mspos 952, reads 5946, writes 33 timeouts 0
Driver 1: standstill, SG min 0, mspos 56, reads 5946, writes 33 timeouts 0
Driver 2: standstill, SG min 0, mspos 360, reads 5947, writes 32 timeouts 0
Driver 3: standstill, SG min 0, mspos 72, reads 5947, writes 32 timeouts 0
Driver 4: standstill, SG min n/a, mspos 648, reads 5962, writes 17 timeouts 0
Driver 5: standstill, SG min n/a, mspos 8, reads 5968, writes 11 timeouts 0
Phase step loop runtime (us): min=0, max=85, frequency (Hz): min=1016, max=8928
=== DDARing 0 ===
Scheduled moves 106, completed 106, LaErrors 0, Underruns [0, 0, 0]
Segments left 0, axes/extruders owned 0x00000007, drives owned 0x00000007
Code queue is empty
=== DDARing 1 ===
Scheduled moves 0, completed 0, LaErrors 0, Underruns [0, 0, 0]
Segments left 0, axes/extruders owned 0x00000000, drives owned 0x00000000
Code queue is empty
=== Heat ===
Bed heaters 0 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1, chamber heaters -1 -1 -1 -1 -1 -1 -1 -1, ordering errs 0
=== GCodes ===
Movement locks held by null, null
HTTP is idle in state(s) 0
Telnet is idle in state(s) 0
File is idle in state(s) 0
USB is idle in state(s) 0
Aux is idle in state(s) 0
Trigger is idle in state(s) 0
Queue is idle in state(s) 0
LCD is idle in state(s) 0
SBC is idle in state(s) 0
Daemon is idle in state(s) 0
Aux2 is idle in state(s) 0
Autopause is idle in state(s) 0
File2 is idle in state(s) 0
Queue2 is idle in state(s) 0
=== Filament sensors ===
Driver 31: pos 2469.02, errs: frame 0 parity 0 ovrun 0 pol 0 ovdue 0
=== CAN ===
Messages queued 3742, received 0, lost 0, ignored 0, errs 3711809, boc 0
Longest wait 0ms for reply type 0, peak Tx sync delay 0, free buffers 50 (min 50), ts 3742/0/0
Tx timeouts 0,0,3741,0,0,0 last cancelled message type 30 dest 127
=== Network ===
Slowest loop: 4.95ms; fastest: 0.03ms
Responder states: MQTT(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0) Telnet(0)
HTTP sessions: 1 of 8
=== Multicast handler ===
Responder is inactive, messages received 0, responses 0
= Ethernet =
Interface state: active
Error counts: 0 0 0 1 0 0
Socket states: 6 2 2 2 2 2 0 2 0

My apologies if it was discussed earlier - i did try to search for similar with no success.

Edit:
Forgot to mention that the package for 3.6.0-rc2 comes with DWC 3.6.0 RC1, and DWC (ver. 3.6.0-rc2) needs to be uploaded separately to avoid error messages

[gloomyandy]

@caviara Are you seeing this movement show up in the X/Y position displayed by DWC?