Added second CC2531, all entities gone unavailable/offline

I’ve rather messed up my ZHA envrironment and not sure how best to recover…

I’ve been running for a while with a CC2531 dongle in my NUC, but I could never manage to get binding working between devices. After reading that this seemed to be better implemented with Zigbee2MQTT, and being under the impression I could dual run that with ZHA (two seperate networks), I plugged a second C2531 dongle into my NUC earlier today. I installed the Zigbee2MQTT addin but it wasn’t starting successfully. I had decided to investigate tomorrow and thought nothing of it until it became apparent that all my ZHA connected devices had stopped working - they’d gone unavailable.

As it seemed likely the second dongle had caused this, I uninstalled Zigbee2MQTT and removed the dongle, but this made no difference. I’ve also removed/replaced my original (ZHA) dongle, plus powered down / up my NUC, but all my entitiies are still unavailable. The dongle must be OK, as I’ve just successfully added a new Aqara button, but none of the old devices appear to want to reconnect.

Am I going to have to delete and re-add all of them? I can’t see any obvious related errors in the logs, though they don’t seem to go back as far as when the devices probably went offline.

I’ve turned on debugging for various things, as suggested in the ZHA troubleshooting section. Too much to paste everything here, but I notice lots of these:

2021-04-16 16:39:43 DEBUG (MainThread) [zigpy_znp.api] Received command: AF.DataConfirm.Callback(Status=<Status.NWK_NO_ROUTE: 205>, Endpoint=1, TSN=45)

Any suggestions?