[hue] CT is updated to UNDEF

[kaikreuzer]

After having set a CT for a light by sending a command, the state is updated to UNDEF after 30 seconds:

2026-06-24 21:16:05.458 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> handleCommand() put resource id:99221d17-33be-43a9-9944-c075ad040fe8, type:light
2026-06-24 21:16:05.582 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateChannels() from resource id:99221d17-33be-43a9-9944-c075ad040fe8, type:light
2026-06-24 21:16:05.583 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'color-temperature' update with '0' (fullUpdate:false, isDefined:true)
2026-06-24 21:16:05.583 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'color-temperature-abs' update with '6451.612903225806451612903225806452 K' (fullUpdate:false, isDefined:true)
2026-06-24 21:16:05.583 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'color' update with '181.5223,3.42900,100' (fullUpdate:false, isDefined:true)
2026-06-24 21:16:05.583 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'color-xy-only' update with '181.5223,3.42900,100' (fullUpdate:false, isDefined:true)
2026-06-24 21:16:05.584 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'dimming-only' update with '100' (fullUpdate:false, isDefined:true)
2026-06-24 21:16:05.584 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'on-off-only' update with 'ON' (fullUpdate:false, isDefined:true)
2026-06-24 21:16:05.584 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'alert' update with 'NO_ACTION' (fullUpdate:false, isDefined:true)
2026-06-24 21:16:05.584 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'last-updated' update with '2026-06-24T21:16:05.584597+0200' (fullUpdate:false, isDefined:true)
2026-06-24 21:16:05.584 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> onResource() consumed resource id:99221d17-33be-43a9-9944-c075ad040fe8, type:light, flags:12
2026-06-24 21:17:11.371 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateChannels() from resource id:99221d17-33be-43a9-9944-c075ad040fe8, type:light
2026-06-24 21:17:11.371 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'color-temperature' update with 'UNDEF' (fullUpdate:false, isDefined:true)
2026-06-24 21:17:11.371 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'color-temperature-abs' update with 'UNDEF' (fullUpdate:false, isDefined:true)
2026-06-24 21:17:11.372 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'color' update with '30.967,87.32800,100' (fullUpdate:false, isDefined:true)
2026-06-24 21:17:11.372 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'color-xy-only' update with '30.967,87.32800,100' (fullUpdate:false, isDefined:true)
2026-06-24 21:17:11.372 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'dimming-only' update with '100' (fullUpdate:false, isDefined:true)
2026-06-24 21:17:11.372 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'on-off-only' update with 'ON' (fullUpdate:false, isDefined:true)
2026-06-24 21:17:11.372 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'alert' update with 'NO_ACTION' (fullUpdate:false, isDefined:true)
2026-06-24 21:17:11.373 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> updateState() 'last-updated' update with '2026-06-24T21:17:11.373122+0200' (fullUpdate:false, isDefined:true)
2026-06-24 21:17:11.373 [DEBUG] [e.internal.handler.Clip2ThingHandler] - 5a47411d-a8bf-4925-93c3-bb3869b2bb6d -> onResource() consumed resource id:99221d17-33be-43a9-9944-c075ad040fe8, type:light, flags:12

I would expect it to report a correct CT value, if nothing has changes since sending a CT command.

These are the Thing properties of a light, where this happens:

Property	Value
resourceType	Device
vendor	MLI
resourceArchetype	Ceiling square
productCertified	false
colorTemperatureRange	6452 K .. 1818 K
firmwareVersion	2.5.3
modelId	RGB-CCT
resourceId	5a47411d-a8bf-4925-93c3-bb3869b2bb6d
productName	Extended color light
thingTypeVersion	1
productArchetype	Classic bulb
hardwareVersion	121b-7d2

[andrewfg]

@kaikreuzer a few observations:

1. The delay varies: in this case it is 66s; and in the other cases reported in [hue] Fix Hue color temperature regression when light is soft-off or unreachable #21018 it is 30s and 42s respectively.
2. In addition to the color-temperature channels becoming UNDEF the color and color-xy-only jump to new values. => Do you see anything on the light itself?
3. It occurs to me that, (analog to [hue] IKEA Trådfri bulb turns off when setting low brightness #21057 where non certified products fail to provide their minimum and maximum dimming levels), there is probably a similar issue that your products fail to provide minimum and maximum mirek levels. This means the binding applies default values of 500 .. 153 Mk (2000K .. 6500K). Which means color-temperature 0% => 2000K (500Mk) and 100% => 6500K (153Mk). So if your lamps have a narrower range than 2000K .. 6500K then your script commands will drive the light off scale.
4. And therefore perhaps the change after the delay of 66s, 42s, 30s is a response to some internal off scale cleaning in the lamp. In such case I would expect if you send 6500K say to the lamp, then after the cleanup it would indeed say CT = UNDEF (off the scale) but probably the color would be a "blue-ish" best attempt. And for 2000K it would be a "red-ish" best attempt. => Does that make sense?

And therefore I think it would be worthwhile if you would test the case where in your script you use color-temperature-abs to send only values within the operating range of your devices.

[andrewfg]

PS I see your lamp has 6452 K .. 1818 K .. so it should probably be OK if you command to OH binding (current) default of 2000K .. but it will probably fall over if you command to OH binding (current) default of 6500K

[andrewfg]

@kaikreuzer on the assumption that my min / max mirek hypothesis is correct, I added the resolution in #21062 (which we should add anyway, even if this issue turns out to be due to something else).