ID already exists - ignoring... when trying to setup "Better thermostat"

Moin,

I am at a loss trying to configure a working zwave thermostat with better thermostat. I can use the thermostat just fine - but when I try to integrate it in better thermostat it is just unavailable and I see the following error in the logs:

Logger: homeassistant.components.climate
Source: helpers/entity_platform.py:613
Integration: Klima (documentation, issues)
First occurred: 08:37:06 (11 occurrences)
Last logged: 08:39:40

Platform better_thermostat does not generate unique IDs. ID 93a3dce737b10ae20783ac8658c5a432 already exists - ignoring climate.better_thermostat_schlafzimmer

I have sadly no clue where to search for the existing ID.

As the winter approaches I would appreciate any advice where to look.