Zigbee Router device sometimes joins to 0x0000000000000000 network after factory reset

[pjbuntinx]

I am using NRF Connect SDK v2.5.2. Sometimes, after I factory reset my Zigbee router device, it will immediately join a network with PAN ID 000000000000. I get this with my project but also with the light_bulb sample. How can I prevent my device from doing this? Below you can view the logs. Just before the logs, the button was held to factory reset the device. The device had not joined a network before resetting. 

Many thanks,

Pieter-Jan

I: Network left (leave type: 0)
I: Joined network successfully (Extended PAN ID: 0000000000000000, PAN ID: 0xffff)
I: Network rejoin procedure stopped.

[AHaug]

Hi

Sometimes, after I factory reset my Zigbee router device, it will immediately join a network

Could you clarify the following when you say "a network":

Do you have multiple networks up, i.e is it a random network it joins? Is it establishing a new network that the router joins?

Do you have a sniffer trace for the device throughout the procedure you describe? 

The log also says I: Network rejoin procedure stopped. Indicating that the rejoin procedure stops

Kind regards,
Andreas

[pjbuntinx]

This happens with or without a coordinator in the proximity. When it is, It does not matter whether the coordinator is allowing new devices or not. The network the device joins is not one that should be existing.
This is not applicable to the light bulb example, but for my own device's code, I am using install_codes. So, it should normally not be possible to join another network without having the correct install code added to the coordinator. 

[AHaug]

Thank you for providing this. 

Based on your description and reproduction in multiple SDKs this seems to be a bug. I've created an internal ticket to investigate this further and I'm currently waiting for some feedback from the Zigbee team for this case.

I'll update you as soon as I know something

Kind regards,
Andreas

[pjbuntinx]

Hi AHaug 

Do you perhaps have any update on this?

Kind regards,
Pieter-Jan

[AHaug]

Hi Pieter-Jan,

The latest update I received from the Zigbee team is they are working with testing and recreating the behaviour reported. I will try to update you before the weekend with any results and/or follow up questions from the team.

Thank you for your patience and kind regards,
Andreas

[AHaug]

Hi again,

The team verifies that the issue is reproducible and they are working on testing a suggested fix and to integrate it. If the test passes it will be targeted for NCS 2.9.0, which should be estimated release some time in Q1 2025. 

Kind regards,
Andreas

[pjbuntinx]

Good to hear! Thank you for the update :)