Bambu Firmware Bug Reporting Thread

We are committed to delivering the best experience in our Bambu Firmware, and we appreciate all the help we can get from you in reporting bugs that might be missed from our trusty development and QA team.

This thread is dedicated to bug reporting, so if you want to help, please share a single post in this thread following this example template:

Problem: Load Filament option not working
Firmware Version:
Printer: Bambu Lab X1-Crabon
Steps to reproduce:

  1. Navigate to the Settings section
  2. Insert filament via the Spool Holder inlet
  3. Touch the Extrude button
  4. Notice that the extruder does not load the filament and nothing is extruded trough the hotend

Log file: Export the log file following this guide:
Other information:
Filament loaded from the spool holder, and not via AMS.
Used Bambu Lab PLA Basic Blue

It is very important to share as much information as possible when posting a bug report. It will greatly help our development team in finding out the root cause of the problem and apply the necessary patches/improvements quickly.

Besides that, every user that reports bugs will be granted the “Bug Reporter” badge!

Thank you for your help!


Problem: Printer stays in preheating bed step.
Firmware Version:
Printer: Bambu Lab X1-Carbon
Steps to reproduce:

  1. Startup the printer
  2. The nozle temperature reports 0 degree
  3. Start a print
  4. Printer stays in the heating bed step and doesn’t continue,
    Setpoint of the nozzle is 230 degrees but actual temperature stays 0 degrees.

Other information:
When restarting the printer, sometimes a couple of times and the nozzle temperature is reading a temperature the machine acts normal.

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  1. Is there error message on the scren? The HMS message at tool head section could be a reference
    HMS Code Index | Bambu Lab Wiki
  2. If the issue is random, can you please share log with us?
    How to update log files to an existing ticket | Bambu Lab Wiki
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The issue is random, I have created a ticket and shared the log.

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Problem: Printer doesn’t turn the back fan off when the PLA/PETG print job is stopped manually
Firmware Version:
Printer: Bambu Lab X1-Carbon
Steps to reproduce:

  1. Start any PLA/PETG print
  2. Wait for the print job to start. I mean, the actual printing with the back fan at full blast, not the calibration process.
  3. Stop the print
  4. The fan will keep at full blast until you restart/shutdown the printer

Other information:
The steps above is all you need to replicate it.
It happens every time and does not depend on any other special factor.

For the matter, this same issue happens with other users so it is no limited to my printer.

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Problem: Printer ignores slicer vitrification settings
Firmware Version:
Printer: Bambu Lab X1-Carbon
Steps to reproduce:

  1. Set the vitrification on the slicer.
  2. Save it, otherwise, the slicer will also give you a vitrification warning ( This does not happen always )
  3. Slice a model as usual
  4. Send to the printer and start it
  5. The pop will comes up like if the firmware itself is overwriting what is specified on the slicer

Other information:

I believe this behavior should be kept on the slicer side like warn you about it.
I have only once sent a job from the slicer (PC) to the printer and no vitrification warning was displayed.
Manually jobs display the warning every time.


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Maybe I’m missing it, but there is a load/unload for the AMS but no option to unload or load external rolls of filament. It doesn’t even cut it. You have to heat up the hot end, press the reverse button the extruder like a million times and then pull super hard to get it out. This doesn’t make sense.


I don’t think any of the users who have reported so far have received the promised “Bug Reporter” badge.

@Hakuna.Matata on the Discord chat server recommended that we have an issue-tracking system for the firmware. I agree! Whenever we submit firmware issues, it is hard to see the state of our firmware suggestions and bugs in the forum (like if they have been acknowledged, planned, in progress, implemented, stale, cancelled, etc.). @Wolf_on_Air on the Discord chat server suggested that you might create a codeless GitHub repository for accepting the firmware issues so users can submit and track the status of issues as they submit them. If you prefer a self-hosted issue tracker for firmware, you might consider Jira among numerous others.


We apologise for the delay, but we are still working on implementing all the workflow for this.
We also need to ensure more consistency in the bug reporting as some users do not follow the guideline and the bug reports are scattered in various sub-sections.
Please allow us a bit more time to work on this and we will do it better.


Problem: Resume after pause procedure moves print head against front wall
Firmware Version:
Printer: Bambu Lab X1-Carbon
Steps to reproduce:

  1. Pause mid print, in my case done through the slicer option “add pause”
  2. While paused move the print head all the way to the front using the UI. Since it is homed it will stop at y=0. I did this to manually remove filament that had accumulated on the nozzle.
  3. Press resume
  4. The resume procedure/macro seems to always move the print head to the front for a bit, even if located at y=0. This results in skipped steps and when resuming the print it results in shifted layers.

Other information:
After being homed the firmware should always know about the print heads total position and a move outside it’s boundaries should never be possible, even for macros.
Feature suggestion:
While in pause mode the UI should give the user maintaining options like:

  • clean nozzle - automatically clean the nozzle
  • clean nozzle manually - move print head to the front
  • manual filament switch - unload filament → load new filament → poop. This one is an important missing feature in my opinion, even for AMS users that may want to manually switch to a 5th filament. Also when using multiple colors in the slicer while not having an AMS attached this procedure should take place whenever there is a filament switch. The slicer could warn the user if there is a lot filament switches in the print and having no AMS attached.

I encountered another case where a macro drives the print head against it’s limits:
Steps to reproduce:

  1. Cancel a print via display UI
  2. Move the print head to the back via UI
  3. Start another print
  4. The print head will hit the back limit and skip steps in this case. The print will not fail since another homing procedure is done before the print.

Not a bug but a feature request

At the end of a print, the X1c consumes abt 30 watt energy. When I add the command M18 at the end, all steppers are off and the cpnsumpti0n reduces to 10 watt.

Look here (;

@M_Key Thats what I said. I am adding M18 at the end of the print since quite a while already.

Someone from Bl mentioned a while back that they would look into this with the new firmware or Studio version. Just wanted to make sure that this is not forgotten


When I send a 3D file from Fusion 360 to the slicer, it opens a new window each time. Running MacOS Big Sur.

After firmware update the printer no longer pauses.
After a bunch of failures, tested slicer 1.3 and 1.4, if you set the printer to pause via the slicer to insert nuts, it keeps printing like nothing happened.

This was working fine before the firmware update.
This is a must have feature.
I am very annoyed at this stage, tired of endless doing this and that to be able to print.

Another user tested this and the printer indeed does no longer pauses.
He is also running the latest firmware.

I tried that yesterday and it did work for me. Latest Studio and FW, MacOS.
I have added the pause command via slicer interface, right click on the + and then click on add pause

There shall be no difference in pause in this firmware. How did you perform the pause action?

The root cause was because printing sequence was set to by object and not by layer.
Prior to the firmware update, that was never an issue.
The slicer doesn’t warn you either, it does allow you to slice as usual and the printer ignores it.
The slicer must now allow you to set pause when in object mode.

Problem: Bed crashes into nozzle with extreme force at beginning of calibration
Firmware Version:
Printer: Bambu Lab P1P
Steps to reproduce:

  1. Home the printer
  2. Start calibration
  3. Bed runs up and crashes into nozzle, causing screeching sound and carbon rods flex upwards
  4. After a second or two calibration continues as usual
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