My ZigBee Light has started to confuse colour temperature and brightness

[dense gate]

I've had a single zigbee light on my HA setup for months, I added a new one to the same area though this one doesn't support colour temperature (only RGB), for ambient lighting.

Since adding the second light, my main bulb's brightness has now become somehow tied to colour temperature, with higher colour temperature resulting in lower brightness. The only way to get full brightness is to lower the colour temperature to 2000K (which is just a bit too warm)

I've tried sending various temp/brightness events via the dev tools (see image) -- and always the colour temperature changes the brightness now.

[urban void]

Sounds like a random Tuya Device...

[dense gate]

It's very odd, I have checked the packets with Wireshark and it's sending the right commands. Like I said this light worked normally until I added an additional one to my Zigbee net

I guess it somehow must be the bulb given the right ZHA commands are being sent... but I'm baffled as to why this would start happenning, if it happened OOTB then I'd accept the device is just bad... but almost a year later?

[hushed turtle]

is the bulb actually updating the brightness? like, when you set a different color temp, the brightness slider in HA moves to a different position?

if you're setting high brightness and the device still reports high brightness, but the result is dim, it also might be that the high-cct leds in the bulb are failing/fading. the bulb might think it's staying the same brightness but the hardware isn't capable any more.