@dc42 Any idea why this could happen? In the meanwhile I tried different slicers, also a different toolboard and a different extruder motor, but I have no idea, why it does slow do that much. I checked all of the mechanics and wiring and everything seems to be right.

@dc42 Hi, sorry now it's uploaded to google drive:

https://drive.google.com/file/d/152xQRM__zzOg7v84xMwgyW9Tk7V_hUEt/view?usp=sharing

@dc42 Sorry it's too big to upload it here.
I uploaded it here:
https://www.file-upload.net/download-14653438/VoronTeileNeuerVersuch.gcode.html

@dc42 And one other detail (don't know if it's relevant) With every speed change (2 times a second) the progress bar under Printing Status is jumping like crazy between 0.6% complete and 78.8% complete and many values in between.

@dc42 Thank you for your quick reply. In fact it's about very short zigzag moves. What's irritating to me is, that the speed drops to 0mm/sec for 1 or 2 seconds and then it raises up again. It's doing that many times in each layer, for each gap it has to fill. That's stretching the printing time in an enormous way and the remaining on one point of the object is making that one spot hotter and hotter, what you will see afterwards in the print.
Should I try to extend the movement queue? How much should I try?
And what's that strange message with the motors may beeing disconnected.

@sourteig And of course my first task was to check the wiring and the crimps. Everything is ok here.

@sourteig I don't know, if this is relevant, but I also tried turning off input shaper, pressure advance and linear advance. No difference without them.

Hello,

slowly I do not know what else to do... I am using Duet Firmware 3.4 beta and my prints are slowing down tremendously during printing. It seems like it has something to do with gap filling. At the beginning everything runs very well and smoothly and at some point the printer becomes extremely slow and the message "Motor Phase A/B may be disconnected by driver X" appears frequently on the display. The values for driver and motor vary with each message. Maybe you can help me here?
Here is my config and the text after a m122:

config:
; Configuration file for Duet3 Mini5+ with Mini2+ expansion (firmware version 3.3 or newer)
; executed by the firmware on start-up

; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves

M669 K1 ; Select CoreXY mode
M564 S1 H1 ; Forbid axis movements when not homed

; Network
M550 P"Voron V2.4" ; Set machine name
M552 S1 ; Enable network
M586 P0 S1 ; Enable HTTP (for DWC)
M586 P1 S1 ; Enable FTP (for remote backups)
M586 P2 S0 ; Disable Telnet

; --- Z Drive map ---
; _______
; | 1 | 2 |
; | ----- |
; | 0 | 3 |
; -------
; front
;
; (looking at the printer from the top)

; Drive directions
M569 P0 S1 D2 ; X motor direction
M569 P1 S1 D2 ; Y motor direction
M569 P2 S1 D2 ; Z0 motor direction
M569 P3 S0 D2 ; Z1 motor direction
M569 P4 S1 D2 ; Z2 motor direction
M569 P5 S0 D2 ; Z3 motor direction
;M569 P6 S1 D2 ; E0 motor direction
M569 P121.0 S0 ; Toolboard Extruder

; Motor mapping and steps per mm
M584 X0 Y1 Z2:3:4:5 E121.0 ; motor bindings
M350 X16 Y16 Z16 E16 I1 ; set microstepping
M92 X80 Y80 Z400 E690 ; set microsteps per mm

; Drive currents
M906 X1000 Y1000 Z1000 E800 ; XYZ and E current
M906 I30 ; Idle current percentage
M84 S120 ; Idle timeout

; Accelerations and speed
M98 P"/macros/print_scripts/setup_printing.g"

; Axis travel limits
M208 X-3 Y0 Z-3 S1 ; Set axis minima
M208 X297 Y304 Z275 S0 ; Set axis maxima

;M208 X0 Y0 Z-3 S1 ; S1 = set axes minima
;M208 X294.4 Y307 Z280 S0 ; S0 = set axes maxima

; Endstops
M574 X2 S1 P"io1.in" ; X min active low endstop switch
M574 Y2 S1 P"io2.in" ; Y min active low endstop switch
M574 Z0 P"nil" ; No Z endstop

; Z probes
M558 K0 P8 C"121.io2.in" T18000 F120 H5 A5 S0.01 R0.2
G31 K0 P1000 X0 Y25 Z1.62 ; (if positive, greater value = lower nozzle. if negative, more negative = higher nozzle)

; Energetic textured plate: Z?
; TL textured plate: Z?

; Bed leveling
M671 X-65:-65:365:365 Y0:395:395:0 S20 ; Define Z belts locations (Front_Left, Back_Left, Back_Right, Front_Right)
M557 X25:275 Y25:275 S25 ; Define bed mesh grid (inductive probe, positions include the Y offset!)

; Bed heater (dual thermistor setup)
;M308 S0 P"temp0" Y"thermistor" T100000 B3950 A"Bed Heater" ; configure sensor 0 as thermistor on pin temp0 (heater sensor)
;M308 S2 P"temp1" Y"thermistor" T100000 B3950 A"Bed Plate" ; configure sensor 2 as thermistor on pin temp1 (mic6 sensor)
;M950 H0 C"out0" T2 Q10 ; create bed heater output on out0 and map it to sensor 2 (mic6 sensor). Set PWM frequency to 10Hz
;M140 P0 H0 ; Mark heater H0 as bed heater (for DWC)
;M143 H0 P1 T0 A2 S115 C0 ; Regulate (A2) bed heater (H0) to have pad sensor (T0) below 115°C. Use Heater monitor 1 for it
;M143 H0 P2 T0 A1 S125 C0 ; Shut off (A1) bed heater (H0) if pad sensor (T0) exceeds 125°C. Use Heater monitor 2 for it
;M143 H0 S110 ; Set bed heater max temperature to 110°C, use implict monitor 0 which is implicitly configured for heater fault
;M307 H0 B0 S0.6 ; disable bang-bang mode and set PWM to 60% to avoid warping

; New Settings:
M308 S0 P"temp0" Y"thermistor" T100000 B3950 A"Bed Heater" ; configure sensor 0 as thermistor on pin temp0
M950 H0 C"out0" T0 Q10 ; create bed heater output on out0 and map it to sensor 0, Set PWM frequency to 10Hz
M140 P0 H0 ; Mark heater H0 as bed heater (for DWC)
;M143 H0 P1 T0 A2 S115 C0 ; Regulate (A2) bed heater (H0) to have pad sensor (T0) below 115°C. Use Heater monitor 1 for it
;M143 H0 P2 T0 A1 S125 C0 ; Shut off (A1) bed heater (H0) if pad sensor (T0) exceeds 125°C. Use Heater monitor 2 for it
M143 H0 S110 ; Set bed heater max temperature to 110°C, use implict monitor 0 which is implicitly configured for heater fault
;M307 H0 R0.900 C275.200:275.200 D2.50 S0.60 V24.3 B0
M307 H0 R0.802 C468.853:468.853 D2.58 S0.60 V24.4 B0 I0

; Hotend heater
M308 S1 P"121.temp0" Y"pt1000" R2200 A"Hotend" ; configure sensor 1 as PT1000 on pin temp1
M950 H1 C"121.out0" T1 ; create nozzle heater output on out0 and map it to sensor 1
M143 H1 S300 ; set temperature limit for heater 1 to 300°C
M307 H1 R2.479 C208.100:177.500 D8.10 S1.00 V24.3 B0 ; disable bang-bang mode for the nozzle heater and set PWM limit

;M308 S1 A"Hotend" P"121.temp0" Y"pt1000" R2200 ; Hotend is 2-wire PT1000 on pin toolboard
;M950 H1 C"121.out0" T1 ; Hotend heater is connected to out1
;M307 H1 R2.479 C208.100:177.500 D8.10 S1.00 V24.3 B0 ; disable bang-bang mode for heater and set PWM limit
;M143 H1 S350 ; Set temperature limit for heater 1 to 350C

; MCU sensors
M308 S2 Y"mcu-temp" A"MCU"
;M308 S3 Y"drivers" A"Drivers"
M308 S5 P"temp2" Y"pt1000" R2200 A"Chamber Temp" ; define temperature sensor

; Fans
M950 F0 C"121.out1" ;Q20 ; part cooler, set to 20Hz PWM
M106 P0 S0 H-1 C"PartCooler" ; Name it "PartCooler"

M950 F1 C"121.out2" Q250 ; hotend fan, set to 250Hz PWM
M106 P1 S1 T50 H1 C"Hotend" ; attach hotend fan to heater 1 and set activation temperature to 60°C

M950 F2 C"out6" Q30 ; electronics compartment fan, set to 30Hz PWM
M106 P2 C"MCUFan" H2 T50 S0.25 ; fan is activated when MCU reports 35°C; runs on full speed from 50°C on

; LEDs
M950 F4 C"out5" ; Create fan 4 (top leds) on pin out5
M106 P4 S110 B0 H-1 C"Top Lights"

; Tools
M563 P0 D0 H1 F0 ; Define tool 0 using fan 1 for M106
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

; Misc
M572 D0 S0.10 ; Pressure Advance
;M592 D0 A0.015 B0.0012 L0.2 ; Non-linear extrusion
M376 H10 ; Fade mesh out compensation over 10mm Z
M912 P0 S-8.5 ; MCU temp calibration

; DAA tuning (you will need to change this for your slicer)
;M593 F26.6 ; Cura 4.5 stock profile @ 40mm/s outer printing speed
M593 F42.5 ; PrusaSlicer @ 40mm/s outer perimeter
M575 P1 S1 B57600

M501 ; load config-override.g

M122:
4.8.2021, 09:40:45 M122
=== Diagnostics ===
RepRapFirmware for Duet 3 Mini 5+ version 3.4.0beta1 (2021-07-10 16:20:41) running on Duet 3 Mini5plus Ethernet (standalone mode) Board ID: JML4W-V296U-D65J0-40KMW-2W03Z-ZWD6G Used output buffers: 1 of 40 (28 max)
=== RTOS ===
Static ram: 102724 Dynamic ram: 102244 of which 188 recycled Never used RAM 35692, free system stack 112 words Tasks: NETWORK(ready,61.4%,214) ETHERNET(notifyWait,0.3%,568) HEAT(delaying,0.0%,344) Move(notifyWait,0.2%,262) CanReceiv(notifyWait,0.0%,773) CanSender(notifyWait,0.0%,357) CanClock(delaying,0.0%,338) TMC(notifyWait,1.2%,72) MAIN(running,34.7%,400) IDLE(ready,1.4%,29) AIN(delaying,0.8%,264), total 100.0% Owned mutexes:
=== Platform ===
Last reset 15:48:33 ago, cause: power up Last software reset at 2021-08-02 20:28, reason: User, GCodes spinning, available RAM 35868, slot 2 Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x00000000 BFAR 0xe000ed38 SP 0x00000000 Task MAIN Freestk 0 n/a Error status: 0x00 Aux0 errors 0,0,0 MCU revision 3, ADC conversions started 56913018, completed 56913018, timed out 0, errs 0 Step timer max interval 847 MCU temperature: min 49.0, current 49.0, max 49.0 Supply voltage: min 24.4, current 24.5, max 24.5, under voltage events: 0, over voltage events: 0, power good: yes Heap OK, handles allocated/used 99/11, heap memory allocated/used/recyclable 2048/548/192, gc cycles 0 Driver 0: position 16301, standstill, SG min/max 0/14, read errors 0, write errors 0, ifcnt 24, reads 1451, writes 0, timeouts 0, DMA errors 0 Driver 1: position -894, standstill, SG min/max 0/16, read errors 0, write errors 0, ifcnt 23, reads 1450, writes 0, timeouts 0, DMA errors 0 Driver 2: position 5520, standstill, SG min/max 2/2, read errors 0, write errors 0, ifcnt 24, reads 1450, writes 0, timeouts 0, DMA errors 0 Driver 3: position 0, standstill, SG min/max 0/0, read errors 0, write errors 0, ifcnt 24, reads 1451, writes 0, timeouts 0, DMA errors 0 Driver 4: position 0, standstill, SG min/max 0/0, read errors 0, write errors 0, ifcnt 24, reads 1451, writes 0, timeouts 0, DMA errors 0 Driver 5: position 0, standstill, SG min/max 0/0, read errors 0, write errors 0, ifcnt 25, reads 1450, writes 0, timeouts 0, DMA errors 0 Driver 6: position 0, standstill, SG min/max 0/0, read errors 0, write errors 0, ifcnt 9, reads 1450, writes 0, timeouts 0, DMA errors 0 Date/time: 2021-08-04 09:40:42 Cache data hit count 4294967295 Slowest loop: 208.40ms; fastest: 0.11ms === Storage ===
Free file entries: 8 SD card 0 detected, interface speed: 22.5MBytes/sec SD card longest read time 2.9ms, write time 0.0ms, max retries 0
=== Move ===
DMs created 83, maxWait 442ms, bed compensation in use: none, comp offset 0.000
=== MainDDARing ===
Scheduled moves 1240500, completed moves 1240500, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 55], CDDA state -1
=== AuxDDARing ===
Scheduled moves 0, completed moves 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
=== Heat ===
Bed heaters = 0 -1, chamberHeaters = -1 -1 Heater 0 is on, I-accum = 0.1 Heater 1 is on, I-accum = 0.0
=== GCodes ===
Segments left: 0 Movement lock held by 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 0, running macro Aux2 is idle in state(s) 0 Autopause is idle in state(s) 0 Code queue is empty.
=== CAN ===
Messages queued 266, received 196, lost 0, longest wait 1ms for reply type 6029, peak Tx sync delay 6, free buffers 17 (min 7), ts 80/80/0 Tx timeouts 0,0,0,0,0,0
=== Network ===
Slowest loop: 370.32ms; fastest: 0.03ms Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0), 0 sessions HTTP sessions: 1 of 8 - Ethernet - State: active Error counts: 0 0 0 0 0 Socket states: 5 2 2 2 2 2 0 0

And here's a video of the strange behaviour:

Voron_2.4_2021-08-04T09_56_04+0200.mp4

I fixed the problem, it was no shortcut. On the board there are some chips. One of them with around 40 pins had 1 pin, that wasn't correctly soldered to the board. The solding ball was not melted. Fortunately a technichan could fix this and soldered it correctly on the board. Now everything works fine.

Nevertheless Thank you all for helping me!

@dc42 I had everything connected. I unplugged all cables except of VIN, then nothing happend after turning on. No LED lit. When I then connected only the 4pin CAN Cable and VIN after powering on, the blue LED lit up again, but not the 5V LED... I did this all with the board not mounted, to exclude shorting over the screws.