I set up a large number of Aqara devices in HA, directly discovering them in ZHA.
Given recent problems getting the Alexa Smart Home skill fully functioning, I decided to add the Aqara entities to the Aqara app using an M2 hub, and then exposing this to the Alexa app.
All seemed to be ok, however, I assume not conicidentally, almost all of my ZHA entities are now unavailable in HA. Two issues follow:
When I try to re-pair the unavailable entities in ZHA, a lot of the time they are not being discovered.
More crucially, when I hit the repair button on the entities, the Aqara app immediately deletes them.
So my question is (and please bear in mind I currently have a total of 121 ZHA devices in HA, so anything is going to be a very time consuming exercise I think), how do I get the unavailable entities back in HA ZHA without deleting them in the Aqara app ?
Zigbee devices can only be paired to a single Zigbee Coordinator, this is a limitation in the Zigbee specification (and not something that can be worked around in any way). Best practise is to factory reset any device before pairing or re-pairing it to a Zigbee gateway (and before doing that you should really first delete them from Aqara app).
https://www.home-assistant.io/integrations/zha#introduction
Hi Hedda
Clearly the wrong answer as it is not the one I want 
However, thank you very much for the very quick response. At least now I know what I have to do - or at least it narrows me down to two options. Either figure out which combination of locale, market place and end point I need to get the smart home skill working, or take the easy (?) option of signing up to Nabu Casa.
Really do appreciate that you took the time to respond.
Most do because that can also as be seen as a sponsorship for Home Assistant developers, without there would not be any developers working full-time on home assisistant and now there is 30 of them → https://www.nabucasa.com/about/
So you do not only get he service but also get more developers working full-time on Home Assistant.