MQTT HomeAssistant discovery incomplete for IKEA Whitespectrum bulbs?

Hi mates,
I’ve been a long-term user of the native Zigbee binding but now started exploring zigbee2mqtt in combination with the MQTT auto-discovery for HomeAssistant components.

Some of my Zigbee devices worked immediately. But I can’t control the color-temp channel of my IKEA Tradfri E14 WhiteSpectrum bulbs:

Problem description

Apparently, the discovery worked - all expected channels seem to got discovered. But the mqtt:homeassistant:mqtt-broker:zigbee2mqtt_xxxxxx:light#color-temp channel is there and can even be bound to an item, but it is not able to communicate with the bulb via MQTT.

Investigation

When looking closer at the discovered channels, I noticed, that for the last two channels no configuration section is visible in the code tab of the thing:

If I understand correctly, the last two channels (including my not working color-temp channel) does not have MQTT topics to subscribe/publish to.

Can somebody confirm similar behavior? Am I doing something wrong here?

Setup

openHAB 4.3.5
OS Debian Linux/5.10.0-9-amd64 (amd64)
Java 17.0.15 (Zulu17.58+21-CA)
zigbee2mqtt 2.3.0
Coordinator EmberZNet 8.0.2 GA (on Sonoff Dongle E)
IKEA Tradfri bulb E14 LED2101G4 Firmware 1.1.20