Pairing failed: Nuki Smart Lock 4.0 Pro via Matter (Echo Dot 5 to Home Assistant)

Unfortunately, I can’t get it to work. I have connected my Nuki Smart Lock 4.0 Pro to an Echo Dot (5th Gen) via Matter. Now, I’m generating the pairing code within the Alexa app to add it as a new Matter device in Home Assistant. After waiting for a short moment, I always get an error message stating that the pairing failed. What could be causing this? My homeassistens is running in a VM on a synology NAS