Can't get groups to work with Sonoff MINI-ZBDIM

[theo-beers]

I'm trying to create a group of 2 Sonoff MINI-ZBDIM devices. They seem to be successfully added to the group, but they do not respond to on/off or brightness adjustments, unlike some groups of other devices I've created.

I found a similar discussion about the ZBMINIL2, but the MINI-ZBDIM is not a device that operates on just the phase wire, so I expect it to not to have the same power limitations.

The product page states that it supports groups.

At the clusters tab of the device, the genGroups feature is available. It just doesn't seem to do anything.

Am I missing something?

[andrei-lazarov]

No, you are not missing anything 😕
Again, I'll update the docs and ask you to contact SONOFF

Maybe share a screenshot of the clusters tab. Does it have multiple endpoints?

[theo-beers]

Yes, it does, but I'm referencing the one with genGroups (endpoint 1):

I also tried to debug using AI assistance, digging through the logs and comparing it them working groups, but it came to the same conclusion. Below is the summary. Feel free to criticise its findings; I'm not an export on this topic ;-) :

MINI-ZBDIM not responding to group commands

Device

• Model: SONOFF MINI-ZBDIM
• Firmware: v1.0.5 (installed_version: 4101, latest available: 4101 — up to date)
• Zigbee2MQTT: debug log level enabled throughout testing

Problem

Two MINI-ZBDIM devices added to a z2m group do not respond to group on/off or brightness commands. Individual unicast control of both devices works correctly.

Investigation

Adding to group

When adding a device to a group, the logs show only z2m's internal bookkeeping — no ZCL addGroup command is logged at the Zigbee level:

z2m: Adding endpoint '1' of device 'sonoff-spot' to group 'spots-group'
z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/bridge/response/group/members/add', payload '{"data":{...},"status":"ok"}'

This pattern is identical to a confirmed-working device on a different group, so this appears to be normal z2m behaviour rather than a bug.

Sending group commands

Publishing {"state": "OFF"} to the group topic produced an immediate optimistic state update on the device's MQTT topic, but the light did not physically respond. Brightness remained unchanged from its pre-command value, confirming the Zigbee frame was not acted upon by the device.

Conclusion

The MINI-ZBDIM advertises genGroups as a supported input cluster, but in practice does not appear to respond to group-addressed ZCL frames. It is unclear whether:

• The addGroup write reaches the device but group multicasts are silently ignored, or
• The group table write itself is failing silently, so the device never registers to listen for group frames

Note: the related ZBMINIL2 group issue (#22705) produces an explicit timeout error on genGroups.add. The MINI-ZBDIM does not throw this error, making the failure harder to diagnose.

Workaround

Control each device individually via Home Assistant automations targeting their unicast MQTT topics directly, rather than via a z2m group.

[andrei-lazarov]

Does it appear as a Router or End Device in Z2M? (End Devices usually don't support receiving group commands)

[theo-beers]

They are reported as a router, and actively routing traffic from other devices according to the network map.