Pairing Problems

Hi Guys,
after 20 hrs of testing I have no idea how to continue.

I am totally new to Zigbee an zigbee2mqtt.

I am running zigbee2mqtt on a RPI 4 (raspbian). Zigbee2mqtt was installed using the official guide without problems.
I bought a CC2531 with pre-installed ZStack 1.2 coordinator firmware (20190608)

I was able to start zigbee2mqtt just fine and can also see the bridge device in FHEM.

Now I am trying to pair 2 devices (TINT Light Bulb E14 an TINT LED Strip).

When I start the pairing absolutely nothing happens in the logs (see attached file)

I have tried to:

  • use different usb ports
  • use a extension cable
  • use channel 25
  • un- and replug the CC2531
  • unplug all othe usb devices
  • put the client-device right next zo the cc2531
  • tried different config options

And I still see nothing in the logs

Debug log:
https://pastebin.com/0Rt34wLj

Config:
https://pastebin.com/4ce4SLh9

Can anybody point me in the right direction ?