Shortly after I upgraded my Unifi access points from 4.3.28 to 5.43.43; I started getting timeout issues. Not all devices, but some; the Raspberry Pi driving our DAKboard, and both our Netatmo air quality sensors.

It took me a while to understand what was happening, and I didn’t immediately relate it to the firmware upgrade.

Table of contents
Update: On 2022-03-03 I upgraded to 5.43.56 — and three weeks later, no devices have disconnected. So, the problem described in this post seems to be fixed 👍

The problem

TLDR: 5.43.43 caused some of my devices to disconnect — 4.3.28 doesn’t.

The Netatmo devices disconnected about every 2-3 days, while the Raspberry Pi about once, or twice, a week.


  • Became unavailable in the Home Coach app and Home Assistant
  • Didn’t respond to ping requests
  • Reported to still have a valid IP in the Unifi controller
  • Came back online after clicking “reconnect” in the Unifi controller

Raspberry Pi

  • Chromium displayed a disconnected error message
  • Didn’t respond to ping requests
  • Got a 169.x.x.x IP, according to the Unifi controller
  • Came back online after clicking “reconnect” in the Unifi controller


I started keeping a log of when the devices got disconnected, and any changes I made. I think this is essential when troubleshooting over a longer period of time, otherwise details and dates will get lost and you may end up with the wrong conclusion.

I tried changing some settings on the Unifi controller, like disabling wireless uplink and minimum RSSI, but it didn’t have any affect…

The thought did cross my mind that it might be firmware related, but I thought other devices would be affected as well. Not just the Raspberry Pi and Netatmo sensors.

I realized it had to be firmware related after I started testing the Unifi U6-Lite in my office, and the Netatmo sensor in that room stopped disconnecting. The U6-Lite runs the 5.60.9 firmware — so newer than the one causing issues on my other access points.

The Unifi controller 6.4.54 became available, and I upgraded (from 6.2.26). It didn’t change anything, same problem. Except for the Netatmo sensor in my home office, which has been completely stable with the U6-Lite and 5.60.9 firmware.


To downgrade the firmware; I selected the access point in the Unifi controller, went to the Config tab, expanded Manage device, and under Custom upgrade I pasted the firmware URL from the Unifi download site.

I started troubleshooting and logging on September 12th, and downgraded the 28th. Since then I have not had a single disconnect with any device 🙂

Closing thoughts

I think I will wait to upgrade to firmware 5.x until a few more minor versions have been released.

4.3.28 was released 2021-02-10, and 5.43.43; 2021-08-26.

Access points that were part of this testing:

  • UAP-AC-IW: Netatmo sensor on the 2nd floor
  • AP-AC-Pro: Raspberry Pi
  • UAP-AC-Lite, later upgraded to U6-Lite: Netatmo sensor in the home office
Since I started writing this post; a new firmware version is available: 5.43.46. I haven’t tested to see if this has the same problem, but I will 🙂

Last commit 2023-12-25, with message: replace emoji slight_smile/slightly_smiling_face