Connect ZBT-02 randomly dropping all connections multiple times per hour

Configuration Zigbee
1

I installed the new Connect ZBT-2 today replacing a Sonoff ZBDongle-E. Migrating my network worked flawlessly and everything seemed to work great.

After a couple of minutes I started to get notifications that some sensors were unavailable. I assumed it was because the network needed to settle. So I gave it a few hours. Hours later they were still dropping out multiple times an hour and immediately reconnecting.

I tried:

  • Waiting for the network to settle (3+ hours)
  • Relocating the antenna but it shows good connection (255)
  • Disabeling my 2.4GHz network
  • Reflashing firmware to previous version 7.5.5.5 (current 7.5.5.6)
  • Changing USB port to the one the Sonoff dongle always used

I never had any issues with the Sonoff dongle. My network works even with the frequent dropouts but all the devices constantly reconnecting puts a lot of pressure on my Zigbee network and I am afraid automatisations will fail to trigger. I use Zigbee for home security so I need it to be reliable.

Any advice is appreciated!

An example:

Screenshot_2025-12-22_00-05-21
Screenshot_2025-12-22_00-05-21344×772 51.8 KB

2

I’ve had the same experience. I’ve seen a few threads where creating a new network was the key to getting it working reliably. I’ve also seen a through stating that updating the device’s IEEE as per Copying the ieee address of an adapter may also work.

I haven’t had time to test either but either way I’ll be setting up a “staging” instance and I’ll try and update the thread.

3

Yeah I migrated from Dongle-P to ZBT-2 and my experience was that ZBT-2 firmware had symptoms of routing problems/failures that I couldn’t figure out how to overcome. I didn’t see much choice but to go back to Dongle-P.

4

By rewriting the IEEE using universal-silabs-flasher worked perfectly. I had been a bit hesitant to try it but it’s worked great over the last day without issues.

5

That’s the exact issues I had before setting the secondary IEEE. I’ve now found it a fair bit more stable given the gargantuan antenna it has!

6

Yeah I used the universal-silabs-flasher to rewrite the IEEE address too.

7

I changed the IEEE address to the one of my previous dongle but that didn’t do anything.

All Zigbee devices (44 total) connect fine and everything works. It just seems like the ZBA-2 resets itself every few minutes making all devices “Unavailable” for a minute or so before everything connects again.

My problem seems to be quite unique as I don’t really find anyone reporting on this issue. So I am wondering if I have a faulty unit.

For the time being I am switching back to the Sonoff dongle as that one works fine for me.

8

So I noticed that some mains powered devices (several LED controllers) would not join with the ZBT-2 with the rewritten IEEE. I setup a second Z2M server with the ZBT-2 and the original IEEE and the issue went away. I then spent some time removing from my HASS Z2M instance to the test server, shutdown Z2M, and then moved over the new files to the server (updating for HASS config options). Now every device I’ve tried can join as expected and the network feels a good bit more reliable.

The Z2M docs talk about repairing routers when issues like this occur but nearly half of my devices can act as routers, I just went for a clean setup.

Honestly, the only think I want now is control of the LED but apparently that is a WIP…