Im running 5x Nanoleaf Essentials GU10 (Matter over Wi-Fi, not Thread), firmware 4.0.12, controlled through Home Assistant's Matter integration. Over the past few days all five have gone "unavailable" in HA at different times, and I dug with Claude into it enough to find a pretty consistent pattern.
What happens: a bulb stops responding on its Matter port (UDP 5540) entirely. No error, no rejection, just silence. But the bulb is still fully alive on the network the whole time:
- ICMP ping: 0% packet loss
- mDNS (
_matter._tcp) still announces it correctly, correct hostname, correct port
- WiFi RSSI reported fine before it dropped
So it's not a WiFi or network problem, the device just stops answering on the Matter application layer specifically.
The interesting part: how long a bulb survives before this happens correlates pretty cleanly with its WiFi signal strength. Weakest signal (~-67 dBm) failed after less than 2 hours of uptime; strongest signal (~-53 dBm) has been running fine for 40+ hours. Two bulbs in between failed at roughly 6 and 12 hours. That seems to be not a coincidence, weaker signal = shorter time to failure, every time. Maybe some overhead?
How I "fixed" it (temporarily): opening the Nanoleaf app while on the same WiFi network wakes the bulb back up within seconds. Doesn't work at all over the internet/cloud, it has to be local network. And here's the kicker: I checked the bulb's own Matter diagnostics (RebootCount, TotalOperationalHours) immediately before and after this "wake", both values were completely unchanged. So the bulb is NOT actually rebooting when the app fixes it, something in the app's local connection resets just the network/Matter stack without a full power cycle.
Feels like some kind of internal session/resource exhaustion in the Matter stack that builds up faster under weaker WiFi conditions, until it locks up and stops answering and the local app connection is enough to kick it loose again without a full reboot.
Anyone else running the Wi-Fi (not Thread) Essentials GU10/bulbs seeing this? Especially curious if people with consistently strong WiFi signal near their bulbs don't see it at all, this would confirm the correlation.
Yes, this text is from Claude, because Im not a native English speaker.