Pairing Philips Hue Being lamp with zigbee stick

Hi all, I have issues pairing the Philips Hue Being lamp with my zigbee stick. The lamp is this one: Philips 3261030P7, and it came in a set with a dimmer switch (Philips 324131092621). I could factory reset the dimmer switch, and it insantly connected to the zigbee stick (I can see incoming MQTT messages and an entry in the configuration.yaml
I have also resetted the lamp following this guide. The lamp flashes, and the connection to the dimmer is gone, but it does not automatically pair with the zigbee stick. Are there any tricks I can try?
Concerning the zigbee stick, it is a Long Range CC2538+CC2592 ZigBee 3.0.2 USB Stick with firmware based on Z-Stack 3.0.2 and MODKAMRU. zigbee2mqtt works (I can see the MQTT messages from the dimmer once it is paired).
Any help would be appreciated, best regards, Daniel