Correct. ZHA or zigbee2mqtt require the stick to be flashed as a coordinator so they control the zigbee net. They cannot be clients or be joined to a preexisting net.
Thanks for confirming that.
Can two separate ZigBee networks coexist with two separate Coordinators each connected to a different Home Assistant?
Will they just choose different operating channels & so shouldn’t interfere with each other?
Can I then just pair devices with either Coordinator & if necessary move them between Home Assistants by re-pairing them?
Yes, except that you will need to manually set the channels in HA. ZHA defaults to channel 15, z2m to 11. They don’t do any sort of scan to see what is in use.
I have figured this out! Well in my case this is what is happening: gpsd is preventing HA from “talking” to this adapter. How did I figure this out? Well, I am one of those people who wants as little snooping on me as possible and part of this is removing the bazillion NTP pings from all these devices. I setup gpsd and chrony on my real HA box which is where this issue was happening. I then wanted to move that NTP setup to my second box…and BOOM this stopped working on that second box. I went back to my real HA setup and stopped gpsd and BOOM it all started to work.
Now I am trying to see how I can use gpsd and not have it conflict - one way I have figured this out is stop gpsd, start HA, then start gpsd and that is working, but not “hardened”.
Hope this helps other people!