I changed the mqtt topic and I found this
https://community.home-assistant.io/t/2-instances-of-zigbee2mqtt-in-hass-os/518470/13
which led me to installing zigbee2mqtt proxy. I now see a device in the proxy pane. When I started z2m on the new pi there wehere some placeholders for key generation and the like. So I have the following content now
homeassistant: false
frontend: true
mqtt:
base_topic: zigbee2mqttwz
server: mqtt://192.168.66.201
user: mosquitto
password: <password>
serial:
port: >-
/dev/serial/by-id/usb-ITead_Sonoff_Zigbee_3.0_USB_Dongle_Plus_640f11dd8cdbed11808aef2d62c613ac-if00-port0
advanced:
network_key:
<some generated keys>
pan_id: 36179
ext_pan_id:
<some generated ids>
log_output:
- console
homeassistant_legacy_entity_attributes: false
legacy_api: false
legacy_availability_payload: false
device_options:
legacy: false
devices:
'0xa4c13850757f1173':
friendly_name: Wohnzimmer-Steckdose
homeassistant:
name: Wohnzimmer-Steckdose
legacy: false
optimistic: true
permit_join: true
As of writing this, I changed homeassistant to true which then also allowed me to use the entities.