Yeelight LED Bulb II (Color) keeps losing connection to the WiFi router.

The title is self explanatory, after a while (and not much, e.g. an hour, maybe less), the bulb loses access to the Internet and the WiFi router it’s connected to as well with no other way to fix it but turning it off and on again.

Some notes about the setup first:

  • I have a cable DOCSIS 3.0 gateway provided by my ISP, running in bridge mode.
  • To it it’s connected a Xiaomi Mi Router 3G (1st gen, dual core, 128MB ROM, 256MB RAM).
  • The router is running the current stable version of OpenWrt (19.07.5), with both the 2.4 GHz and 5 GHz radios emitting different SSIDs. WiFi 4 is at channel 1 (2412 MHz, 40 Mhz width), WiFi 5 is at channel 52 (5260 MHz, 80 MHz width), none of the channels have any interference.
  • Max 15 clients connected to the router, usually just 6, barely any load at all, I’ll attach some stats of the last day for example.
  • SSIDs are a simple word, e.g. “Xiaomi” and “Xiaomi 5G”, password is the same and just 10 digits, no symbols, no letters.
  • WiFi security is mixed WPA2/WPA3 PSK, SAE (CCMP), the bulb is connecting to the 2.4 GHz using WPA2 (so WPA2-AES it is).
  • The bulb itself is located in the same room as the router.

Now, the bulb is perfectly capable of connecting to the router, it does it after powering on. Both LAN and remote controls work and DNS servers in use are with as an alternative, the IP address is assigned by the router’s DHCP server although it’s a fixed lease (e.g.

After a while it loses all connectivity, I can’t even ping it from the router itself, I have to reboot the bulb for it to work. It is currently running the latest published firmware as of December 2020, 2.0.6_0065.

It is not connected to any home automation handler like Home Assistant either, just a simple bulb, added through the official Yeelight app and with LAN controls enabled.

It seems to be a problem with the firmware of the bulb itself, and I’m willing to help diagnose and troubleshoot if needed. For example, if there’s a way to monitor the light traffic, run some debug firmware on it that reports anything to you (Yeelight, the bulb is not restricted from contacting the Internet in any way) or experimental code. If there’s any log stored inside of it I can provide it too if you detail the steps to acquire it, anything, but I do believe a fix ought to be issued (no other IoT device or otherwise is showing those symptoms, including some based on the same radio hardware the bulb is running on).

Thanks for reading me, for your time, guidance, etc. I hope the root cause can be identified soon and a new firmware deployed for these kinds of bulbs.

I’m at your disposal Yeelight.

1 day router load:

1 day router memory:

1 day 2.4 GHz stats: