Hi,
I didn’t try that option, but I have the same result after some hue and HA update, but after a few days the issue was back.
How long ago was that test? Did you manually create after any new scenes or routines? And if yes, the issue reappeared or stabilized? Any HA update was also installed after?
Thanks in advance!
I don’t have any long term experience. I cleaned the bridge 2 days ago and it works fine. Didn’t have any issues anymore since then.
I configured several dimmer switches with hue app but no further scenes since I manage them via HA.
Unfortunately I can’t tell anything about changes after an hue or homeassistant update yet. I will keep watching it and can give you an update later.
Yes I woud love to create this sort of automation. I have the same “unavailable” issue
In my case I have my 2.4GHZ WiFi on Channel 1, my Hue Zigbee network on channel 25, and my smart things Zigbee network on Channel 11.
I did clean up the Hue hub once but the problem persists. I even changed the Zigbee channel to 25 so to not overlap with my WiFi (channel 6). Nope. Same behaviour. The Hue lights still go unavailable.
I’ve just finished reading 3yrs of a post with sadly no firm solution to the same problem I have… bugger 
I’m running hue integrations and just realize that we need to activate allow unreachable bulbs to report their state correctly. However when the state unavailable it will report the last remain status. So it will create a new problem for me.
Anyone figure this out? So far I’ve:
I am just above the 50 bulb soft limit so I’m going to start migrating some rooms to my ConBee stick. I’d like to keep some zones on Hue for my Sync Box and Hue Labs…
Sounds like u are pushing limits
Yep still having the issue here.
The goofy thing is that I have six bulbs, and only two of them seem to be having the problem.
In my case the problem has gone away. I am running on Raspberry Pi4 and I have reinstalled Home Assistant on Micro SD Card Application Class 2 as discussed in suggested hardware.
Thank you! This was my issue.
I’ve got a Philips Hue (signe) configured with Phoscon via Zigbee.
In the beginning it all worked seamlessly but for the last couple of months it becomes unavailable multiple times a day. Whereas in the Philips app itself the light shows always connected.
Any idea what to do?
I just stumbled upon this thread having this exact error. I frankly didn’t read every single post, but on my end, while I can control the lights in the Hue app, I realized by going in the Settings → Lights from the Hue app that none of my devices were reachable. I still can control them with the group/room feature within the Hue App, or the entity in Home Assistant. Therefore, I don’t think the issue is on the home assistant side. I wonder if it is the same behavior for you guys.
TL:DR Make sure to test your single lights in the Hue app, not the rooms toggles. On my end, they also show unavailable in the app while the rooms toggles still working. Not sure of the root cause of this yet.
What helped at my side was: in the Hue-App changing the Zigbee channel. Before you do this you must turn on ALL Hue lights.
This solved it for me too, I had to change twice as the first change switched from channel 20 to 15. The second changed to 25 and bulbs have not gone ‘unavailable’ for 12 hrs. Fingers crossed 