Light no longer dimmable through Home Assistant (wrong supported_color_modes type?)

Hello. I have a Zigbee light that was previosly dimmable through Home Assistant, but is no longer so. It’s part of an automation that lowers brightness at night and increases it in the morning. And I noticed that it had stopped working recently, I believe after I had upgraded Home Assistant to the latest version.

I see in Development tools that this light has supported_color_modes set to onoff, while another Zigbee light that dims just fine has the property set to brightness.

How can I correct the supported_color_modes value of a Zigbee device?

What brand is the light?

It’s an Ikea E27 bulb. But my other Ikea bulbs work fine.

EDIT: The light is identified in deCONZ as a 1000lm Color Temperature Light, while the others are 600lm Color Light or 400lm Dimmable Light.

The offending bulb is Color temperature light 3, that it is added to a group and controlled in Home Assistant.