I have fond where is issue but dont understand what it appear now.

When I worked to my tpost0.g at begin of configuration of my tool changer I needed to add M564 S0 for allow my printer arm to catch tool0 outside of limits of my bed to make some thing more clean I had added M564 S1 to activate again limits, after that when I tried to printing one problem is appear where my DC42 IR prob dont allow me to printing correctly because the offset not be able to going more dow the the IR prob zone detection, in this case I had removed M564 S1 at end of my tpost0.g and all worked find.

Now to resolve my issue I had added again M564 S1 at end of my tpost0.g, but I had also added M564 S0 at end of homeall.g and now it's work like a charm. But what the problem coming today I dont know

I had do new step in identification of issue. When I manually execute this sequence I haven't problem mesh compensation work well:
1 - power on print
2 - Home all
3 - tpost0.g(macro)
4 - Mesh compensation

But when I execute manually this sequence I have issue
1 - power on print
2 - Home all
3 - tpost0.g(macro)
4 - Home all
5 - Mesh compensation

Issue is locate at second Home all juste after my arm catch tool0.

I juste find some thing, I can have this issue with manual mod, I explain me. When start my printer and home all and execute mesh compensation all is good, but after if I execute my macro like tpost0.g and try again to start mesh compensation I have same issue than when I start printing and probing before printing.
The problem is locate in tpost0.g but I dont know where.

; tpost0.g
; called after firmware thinks Tool0 is selected
; Note: tool offsets are applied at this point!

M116 P0                  ; Wait for set temperatures to be reached
; Note that commands preempted with G53 will NOT apply the tool offset.
M98 P"/macros/ToolChanger/tool_unlock.g" ; Unlock the tool

G53 G0 X132 Y0 F7000  ; Rapid to the approach position without any current tool.
G91
M564 S0
;M302 P0                  ; Prevent Cold Extrudes, just in case temp setpoints are at 0
;G1 E10 F100              ; Purge the Nozzle
;G4 S1                    ; Slight Delay
;G1 E-1.0 F2000           ; Perform a retract to remove filament pressure.
G91                      ; Set Relative Movements
G1 Z3                    ; Pop the Z up slightly to avoid scraping carriage limit switch on pull-back for early layers.
                         ; Also clear any dangling debris on purge towers.
G90                      ; Restore Absolute Movements
G53 G1 Y-80 F6000
G53 G1 Y-80.5 F6000
M98 P"/macros/ToolChanger/tool_lock.g" ; Lock the tool
M98 P"/macros/ToolChanger/tool_lock.g" ; Lock the tool
M98 P"/macros/ToolChanger/tool_lock.g" ; Lock the tool
G53 G1 Y0 F6000        ; Retract the entire tool and wipe Backwards.
;G53 G1 Y336 F10000       ; Wipe Forwards.
;G53 G1 Y296 F10000       ; Wipe Backwards.
;G53 G1 Y336 F10000       ; Wipe Forwards.
;G53 G1 Y296 F10000       ; Wipe Backwards.


;M564 S1
;G1 R2 X0 Y0 Z0   ; Restore prior position now accounting for new tool offset
;G1 X0 Y0 Z0   ; Restore prior position now accounting for new tool offset

M106 R2           ; restore print cooling fan speed

Hi!
Today I have strange issue with mesh compensation, yesterday probing before printing worked well, and this morning I had this when I'd prob my bed before printing, and probing finish with this this message:

Warning: the height map has a substantial Z offset. Suggest use Z-probe to establish Z=0 datum, then re-probe the mesh.
16 points probed, min error -0.465, max error -0.102, mean -0.279, deviation 0.103
Height map saved to file 0:/sys/heightmap.csv

But if I using mesh compensation manually on the dashborad all is ok:

I had investigated but no find the reason of this issue. I using RRF3.1.1, and maybe that is linked with other strange issue I have where my printer arm try to catch my tool0 at old place at first execution of it and catch at right place at second execution of the script. I had posted some days ago about this issue her https://forum.duet3d.com/topic/16740/bug-moving-to-ghost-position

Her some files can help you to help me and my start script in Simplify3D, thx!
start script:

M291 P"Homing all axis" R"Printing.." S1 T2
G21		; metric values
G28		; home all
;G29 S2		; mark if you want to disable mesh grid
;G32 S1		; Run mesh grid compensation
G29 S0
		; Purge extruder
M83		; Set relative extrusion mode
G92 E0 F100		; reset extruder
G1 Z10 F3000 		; move z up little to prevent scratching of surface
M98 P/macros/Filament/Purge	; Run nozzle purge macro
;G1 E-1 F2000		; Retract 1mm filament
G92 E0 		; reset extruder
M291 P"Printing started !" R"Printing.." S1 T3

bed.g
config.g
homeall.g
homeu.g
homex.g
homey.g
homez.g
tfree0.g
Toffsets.g
tpost0.g
tpre0.g

So, about offset issue I have found where is problem, in my tpost0.g I added at end M564 S1 to enable switch limit because at begin of the script I added M564 S0 to disable limit switch for catch my tool who is outside of the limits of my bed. If you have subjection to catch my tool outside of limits of my bed more properly I take it.

I tried one more time to catch tool with G91 before G53 G0 X132 Y277 F7000 but arm continue to go to X285 Y277. My adjustment with G9 after G53 G0 X132 Y277 F7000 work well but I would like understand why it does it, If I have another issue I'll never sure it isn't linked with it, it's what is arrive with my nozzel offset juste now, but it's look like bug.

@droftarts @dc42 If you want do see that in action I send to my Mega account one video, size of it is 91,5Mo :
https://mega.nz/file/y6JB3Q4Y#SHjvxN_g9LJGu5JN3Q662O32qZMaMwiWMbMJgRJJJMs

@droftarts @dc42
Thank you, her my both files

tool-unlock.g

; Disengage the toolchanger lock

G91                 ; Set relative movements
G1 U-4 F9000 H2     ; Back off the limit switch with a small move
G1 U-360 F9000 H1   ; Perform up to one rotation looking for the home limit switch
G90                 ; Restore absolute movements

tpre0.g

; tpre0.g
; called before tool 0 is selected
;
; generated by RepRapFirmware Configuration Tool v2.1.6 on Mon Jan 13 2020 20:14:53 GMT+0100 (heure normale d’Europe centrale)

; Runs after freeing the previous tool if the next tool is tool-0.
; Note: tool offsets are not applied at this point!

G0 X132 Y277 F7000  ; Rapid to the approach position without any current tool.

G60 S2               ; Save this position as the reference point from which to later apply new tool offsets.

You need to remembre macro dont work when I click it once but work when I click on seconde time.

I tried to erase SD card en make clean install but the problem is continue, I had changed folder directory of macro and renamed it, same problem.
That's possible the duet hardware memory my old toolchanger parking position some where?
I seen also G10 Z offset positive value(to reduct gap between nozzel and bed) haven't effect now, only negative value work, that's big problem I can't printing and maybe both problems is linked.
I think to erase duet but it's dangerous thing, I would like to have your help before.

Hi!

At this time I convert my pinter single nozzle BLV mgn Cube to tool changer Jubilee system, I'had update RRF3.1.1.

During my tests I had experiment an strange bug, when i click on my marco one time for go to be in line position whit tool0 parking I see printer arm go to take tool0 on old line parking position, it was been X285 Y277 in past and dont exist anymore in my marco the new one is X132 Y277, when I click in my macro second time the good sequence is play.

Here my marco to take tool0:

; tpost0.g
; called after firmware thinks Tool0 is selected
; Note: tool offsets are applied at this point!

M116 P0                  ; Wait for set temperatures to be reached

; Note that commands preempted with G53 will NOT apply the tool offset.
G91
M98 P"/macros/ToolChanger/tool_unlock.g" ; Unlock the tool

G53 G0 X132 Y277 F7000  ; Rapid to the approach position without any current tool.

M564 S0
;M302 P0                  ; Prevent Cold Extrudes, just in case temp setpoints are at 0
;G1 E10 F100              ; Purge the Nozzle
;G4 S1                    ; Slight Delay
;G1 E-1.0 F2000           ; Perform a retract to remove filament pressure.
G91                      ; Set Relative Movements
G1 Z3                    ; Pop the Z up slightly to avoid scraping carriage limit switch on pull-back for early layers.
                         ; Also clear any dangling debris on purge towers.
G90                      ; Restore Absolute Movements
G53 G1 Y357 F6000
G53 G1 Y357.5 F6000
M98 P"/macros/ToolChanger/tool_lock.g" ; Lock the tool
M98 P"/macros/ToolChanger/tool_lock.g" ; Lock the tool
M98 P"/macros/ToolChanger/tool_lock.g" ; Lock the tool
M98 P"/macros/ToolChanger/tool_lock.g" ; Lock the tool
G53 G1 Y277 F6000        ; Retract the entire tool and wipe Backwards.
;G53 G1 Y336 F10000       ; Wipe Forwards.
;G53 G1 Y296 F10000       ; Wipe Backwards.
;G53 G1 Y336 F10000       ; Wipe Forwards.
;G53 G1 Y296 F10000       ; Wipe Backwards.


M564 S1
G1 X0 Y0 Z0   ; Restore prior position now accounting for new tool offset

M106 R2           ; restore print cooling fan speed

I tried to find where come from the problem, It's when I had execute commands one by one I have locate where is the problem, at begin of my marco I have it:

; tpost0.g
; called after firmware thinks Tool0 is selected
; Note: tool offsets are applied at this point!

M116 P0                  ; Wait for set temperatures to be reached

; Note that commands preempted with G53 will NOT apply the tool offset.
G91

M98 P"/macros/ToolChanger/tool_unlock.g" ; Unlock the tool

G53 G0 X132 Y277 F7000  ; Rapid to the approach position without any current tool. 
...

When 'G53 G0 X132 Y277 F7000' is execute at line 12 the pinter arm go to X285 Y277, if I move 'G91' from line 8 to line 13 like this all working fine it go to X132 Y277:

...
M98 P"/macros/ToolChanger/tool_unlock.g"
G53 G0 X132 Y277 F7000 
G91
...

I dont think is normal comportement and I think I can have some issus with that in the future. Maybe that can be an interesting bug for @dc42 .

Thank you.

@dc42
Finally I have small difference but not significant difference...

With metal plate, cold bed and paper aluminum border exceed

With metal plate, hot bed at 60°C and paper aluminum border exceed