Sonoff ZBDongle-E (V2) - Silicon Labs Flasher ignores firmware version & sensors drop offline

Hello everyone,

I'm a beginner and I've been struggling for over 6 hours to get my Zigbee network stable. I have a problem that I can't solve, and I might be missing something fundamental.

My Setup:

  • Dongle: Sonoff Zigbee 3.0 USB Dongle Plus V2 (Model E).
  • Connection: Connected via a USB extension cable.
  • Environment: Small apartment (28 sqm).
  • System: Home Assistant OS with ZHA integration.
  • Wi-Fi: 2.4GHz channels are configured to avoid interference.

The Problem: I have a motion sensor and a light switch in the bathroom.

  1. In the Home Assistant UI, I can see the sensor state changing (it correctly shows "Detected" when there is motion).
  2. However, the automation often fails to turn on the light. It works for a few minutes after a reboot, then stops, even though the sensor status is still updating in HA.

Firmware Issue: I tried to update the dongle firmware using the "Silicon Labs Flasher" add-on (v0.5.0), but:

  • The logs say: WARNING: No firmware found for the selected device, assuming firmware is installed.
  • If I try to manually add firmware_version: "7.4.3.0" in the add-on configuration, the system automatically deletes this line as soon as I click "Save". I cannot force the update.

What I've tried:

  • Re-paired devices multiple times.
  • Moved the dongle away from the server using a cable.
  • Checked and fixed Wi-Fi channels.
  • Re-enabled ZHA after it accidentally got disabled.

Why does Home Assistant see the motion, but the light doesn't respond? Is this a firmware issue with the V2 dongle, or a bug in the Flasher add-on that doesn't allow manual overrides?

Please help, I'm completely stuck!

Why would you assume it's a firmware issue when you're saying the sensor is still updating correctly?

If you can also control the bulb all the time, it's almost certainly an automation issue. Check your automation traces to see why it didn't run.

Also, might be a good idea to share your automation (& traces) so people here can help you.