Tried a core downgrade as described in this HAOS issue comment. I was wondering if anything in those resulting logs grabs your attention.
So far it seems that a reflash might solve my Conbee II problems.
It looks like my Conbee II device is broken. Today I tried:
- Flash in windows 8: device driver installation unsuccessful with the usual unhelpful windows message: “Something went wrong when installing…” Gave up after 10m trying to understand event logs…ugh!!!
- Installed deCONZ on my laptop and enabled full logs: same timeout errors that I’ve been getting in HA.
It seems to me that the simplest explanation is that the device is broken.
Now you can get something better 
There is a good summary of devices here Supported Adapters | Zigbee2MQTT
Those would apply equally to ZHA or Z2M, I think not deconz.
Thanks! I’ll check it out.
What do you guys think of the Sonoff? It has the high-power chip, AL case, antenna…Definitely looks better in specs than my Conbee. But the latter was well regarded and recommended when I bought it last year. Or maybe I didn’t research it enough…
No experience with the sonoff personally, although many seem to use it fine, but I use the ZZH stick which is the first stick listed in the post from Nick above.
Shipped fairly quickly from UK and wasn’t all that expensive - I’ve never had an issue with it. I’m using zigbee2mqtt but I’ve tested it with ZHA as well and it works with that too.
Thanks for sharing your experience with the ZZH stick, Tim!
Also, for anyone that uses the Conbee: it can be flashed (at least on a linux system) if it is seen by the system, even when it is not working otherwise, which was my case.
I had to install deconz on my laptop to do that. It started working fine after that!
It is beyond me why the deconz addon/container kept trying to connect to the stick instead of at least offering to fix the problem by reflashing it. It was the first thing that the vendor mentioned when I described the connection issues while asking for warranty replacement.