Need help figuring out why Zigbee lights disconnect

I set up a home assistant server with a Sonoff Zigbee dongle and added six Sengled lights to it (all within 20’ of the server. The bulbs are set to change tone throughout the day. It works fine except that fairly often the bulbs seem to disconnect. When I turn on the lights at the wall switch the lights flash through a color sequence (I think the same sequence as when they were new) and no longer update color throughout the day. If I go into my Zigbee settings and click add devices the bulbs get added back immediately.

I recently left the server off for about a month and the bulbs did not flash the connection sequence once but as soon as I turned the server on a few of them did with a day. This makes me think the server is doing something to disconnect them as the bulbs didn’t act disconnected on their own even when there was no server present. Where can I look to find the source of this problem. Thank you.

Have a look at…

Is your dongle on an extension lead to keep it away from interference?

Six routers is not many, and 20 feet may be quite a long way in some cirumstances. Are you using ZHA? If so, the network visualisation tool can be quite useful in identifying problems - paths between routers are coloured to show how healthy they are.

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Sengled bulbs are not routers ! They are specially designed not to be.

Ah! Well, no routers at all is even less. :laughing:

When in doubt, add more Zigbee Router devices and also do your best to actively avoid interference.

Recommend buying a few “known good” dedicated Zigbee Router devices when getting started with Zigbee so that those can act as the backbone of your Zigbee network mesh (being always available).

Zigbee signals are weak and very susceptible to RF noise / EMF interference so check out all these :

https://community.home-assistant.io/t/guide-for-zigbee-interference-avoidance-and-network-range-coverage-optimization/515752

(above is my extended version of https://www.home-assistant.io/integrations/zha#zigbee-interference-avoidance-and-network-rangecoverage-optimization with more details and related discussions.

https://www.home-assistant.io/integrations/zha#defining-zigbee-channel-to-use

https://www.home-assistant.io/integrations/zha#using-router-devices-to-add-more-devices

https://www.home-assistant.io/integrations/zha#best-practices-to-avoid-pairingconnection-difficulties

https://www.home-assistant.io/integrations/zha#zigbee-network-visualization-in-zha-ui

I’d start by unhiding the LQI entity for the bulbs and tracking whether you see this drop low and possibly cause a disconnect. Or check your system logs as you notice the bulbs going offline to see if there are any clues in there.

Also, is there any chance these are being turned off at the switch and losing power ? As you must know, even in an ‘off’ state, smart bulbs must always have power.

Sorry about the delay I didn’t realize I had any replies. Thank you for all of them.

Yes the dongle is on an extension. Yes I am using ZHA. I’ve got one green connection, four yellow and one that does not show a connection but is controllable through HA.

The server and bulbs are in the same room. The bulbs used to be on a hubitat hub that was two floors away and I never saw them flash their pairing sequence.

The bulbs are on physical switches but hubitat and smarthings before that never lost them if they did get flicked off though perhaps this is handled differently in HA. I will look into unhiding the LQI and see what that tells me.

Am I correct in assuming that since my bulbs never flash their pairing colors when HA is off that it is HA initiating the disconnect and to do so would mean it can communicate with the bulbs?

Thanks again everyone.