I just had a power outage and when the power came back on, I have 5 bulbs (LIDL brand) that have disconnected from Zigbee2mqtt. The other bulbs (IKEA brand) are not disconnected.
The server and the boxes are properly connected to a UPS
I had to manually re-pair them, and Z2m found them again
Is there a way to prevent this from happening again?
What you describe is a known behavior of LIDL bulbs: they haven’t really « disconnected, » they’ve reset to factory settings. Their reset sequence is a series of quick power cycles, and unstable current return (micro-cuts, bounces when power is restored) can trigger it involuntarily. IKEA bulbs require a longer sequence (6 cycles), which is why they held up. The fact that Z2M « found » them again during re-pairing (same IEEE address) supports this.
To confirm: if they were flashing when power returned, it was pairing mode. You can also check the Z2M logs at the time of the outage (event device_leave or total absence of messages).
Unfortunately, there’s no setting in Z2M or Gladys to disable this reset; it’s in the bulb’s firmware.
Okay, thanks, I couldn’t see if they were blinking when the power came back because I wasn’t there, and when I returned they were steady. There must have been some power outages because the UPS only reported 2 outages in 10 minutes.