How to properly replace a broken ZigBee coordinator?

I found quite many posts that say it is not possible to use hardware flow with this stick and many post that say it has some design flaws:

https://community.openhab.org/t/zigbee-coordinator-for-new-setup/124015/9?u=anpro

While startup I receive the following error: Error 0xffff setting client binding

I have 19 battery operated Sonoff Mini Motion Sensors
3 battery operated Wallswitches

And the following non battery powered:
22 Light bulbs
8 Sonor Mini Switches

But I no battery operated device is away more than 5 meters from the next „normal“ device.

Any proof (log files etc.) that communication problems are the root cause? Any battery operated Zigbee devices involved?

What do I have to look for - for me log files look normal after start - and every device works flawlessly.
The only point is the long startup phase.

Edit: just read what you did with the Lidl gateway- cool - I guess the benefits are:

  • stable network because of the better antenna
  • more options to place it because connected via Ethernet
  • when you restart openhab you do not have to restart the gateway and all the devices are back online

Is it possible to use the netbackup with the haked Lidl gateway?