Update: We made a mistake trying to help people determine if they could be impacted. The problem doesn’t seem to lie within Home Assistant but with NodeRed. Yet, nothing is confirmed. The article has been updated to reflect that.

In an announcement on their forum yesterday, Bambu Lab explained they have had to put some limitations in place for using their MQTT service.

For those not familiar with MQTT (Message Queuing Telemetry Transport), it’s a protocol widely used with IoT devices to communicate with them. In the case of Bambu Lab, the MQTT protocol provides the state of your printer, the current print, etc.

The MQTT protocol used to be accessed locally by third-party software (like Home Assistant, XTouch, etc.). However, with the new limitation introduced in the latest P1 series firmware, most software has started using an online MQTT service provided by Bambu Lab.

One of those software programs, which appears to be related to NodeRed, commonly used with HomeAssistant, is misbehaving and makes a lot of requests to the service. This could lead to bad performance or complete denial of service. Therefore, Bambu Lab has put in place a temporary ban on misbehaving accounts. This could go from a 24-hour ban to up to a week.

Bambu Lab states the following regarding the ban:

During the ban period, the corresponding account cannot connect to the MQTT server through official or third-party Client software. The corresponding Client will not be able to remotely control the printer or view printer status information through the cloud, but can still initiate printing through Banbu Studio or Banbu Handy. After the ban period ends, the account will resume normal connection. If an exception occurs again, it will still be banned.

This is a temporary measure as they are developing a new maximum connection limit per account for their MQTT service. They expect this new limit to be deployed in August. Until this is deployed, Bambu Lab recommends not using any third party using the MQTT service to avoid potential temporary bans.

If you use any third-party software that triggers this ban, the best you can do is contact the developers and let them know their code is misbehaving. As far as we know, this issue does not affect the new XTouch firmware.