MAC channel access failure

[shell ibex]

Hello,

I recently installed 18 light bulb outside below my roof (this model https://www.zigbee2mqtt.io/devices/IM-CDZDGAAA0005KA_MAN.html#adeo-im-cdzdgaaa0005ka_man)

I am experiencing a persistent issue with my Zigbee network managed by Home Assistant and Zigbee2MQTT. The error occurs frequently and reliably, affecting multiple devices, but also when sending a command to a single router device.

The specific error message is: Error: ZCL command 0x... genLevelCtrl.moveToLevelWithOnOff(...) failed (Data request failed with error: 'MAC channel access failure' (225))

1. Network Configuration
   Zigbee Coordinator: Silicon_Labs_Sonoff_Zigbee_3.0_USB_Dongle_Plus_0001-if00
   Zigbee2MQTT Channel: 25 (Optimal for minimal Wi-Fi overlap).
   Wi-Fi 2.4 GHz Channel: 1 (Optimal for minimal Zigbee interference).
   Devices: All affected devices are mains-powered Zigbee routers (smart bulbs).

2. Steps Already Taken (RF Optimization)
   Based on common troubleshooting advice, I have already taken the following steps, which initially resolved the issue, but the error has now returned:

RF Isolation: The Zigbee coordinator is connected via a USB extension cable (approx. 50cm) to isolate it from the host device (Home Assistant Box).
Port Change: I have tried connecting the dongle to a different USB port to avoid localized USB 3.0 interference.
Distance: I have physically moved my powerful Wi-Fi router (ASUS RT-AC2900) further away from the Home Assistant box.
Automation Delay: I have ruled out network saturation by confirming the error occurs even when sending a single, isolated command.

Don't know what to check and to do next.

Any advice please ?

Thx you

[shell ibex]

here is the map
don't bother other than alleex and jardinx

[jolly sinew]

Hi, I am no Zigbee expert. But let me tell you what I see in your map:

1. All your devices are directly connected to your coordinator. That doesn’t look good/normal. Zigbee bulbs are typically mesh routers/repeaters. There are some bulbs on the market, that do not work (very good) as a router. Maybe you have such bulbs. Which brand/model?
2. Some of your bulbs are not connected, At least this is what the map show. Are your bulbs all online?

The device ‘Price garage‘ has a LQI of 0. It seems the device is to far away.

On the Zigbee2MQTT device page in the Z2M web ui, you see all your devices. There are 4 buttons per device on the right-hand side. Try to reconfigure and interview your devices with a missing connection in the map, even though that won’t help you, with your issue.

This is how my map looks like. I do not have many Zigbee devices. I am more invested into Matter over Thread.

[shell ibex]

hello @jolly sinew thx you for the answer

the other device not connected are "normal", i switched them off

i try to run some test

on the photo you can see the coordinator
the light is connected to the coordinator directly. How come the LQI is only 70 ??
It's litteraly 1.5m away from the coordinator and the antenna is pointed directly to the light

i excluded those switched off device and generated another map

lumiere bureau is the light you can see on the photo. The link says 181 LQI but the device himself says 71
i'm confused :/

[jolly sinew]

You physically switch off some of your Zigbee light bulbs (routers) so that they no longer have power. In this case, your Zigbee mesh network will need to be remeshed. I don't know how long this process takes in a Z2M network. This may be the problem.

You can try to not switch off your light bulbs physically for a few days. If that helps, you know the source of your issues.

I have a cod.m coordinator connected via Ethernet with a CC2652P7 chipset:

https://shop.codm.de/ZigBee-Coordinator-CC2652P7-CZC-1.2/90810-POE-SW

So it’s not comparable to yours, imo.

[shell ibex]

@jolly sinew i juste bought a smlight slzb-06. Will see if it's better or not