Templating: Customizing favorites in Sonos Custom Card

Hi guys,
I’m trying to customize the displayed favorites in my Sonos Custom Card. Therefore I use the following template to exclude favorites that don’t contain a special paraphrase:

{% for item in state_attr(‘sensor.sonos_favorites’, ‘items’).values() |
reject(‘match’, ‘NDR’) | list %}
- {{item|e}}{% endfor %}

The output in the Template Editor looks fine:


After that I added the code to the favoritesToIgnore property:

favoritesToIgnore: >
{% for item in state_attr(‘sensor.sonos_favorites’, ‘items’).values() |
reject(‘match’, ‘NDR’) | list %}
- {{item|e}}{% endfor %}

But it doesn’t have the desired effect. The favorites are empty.
Adding the output of the Template Editor to the favoritesToIgnore property leads to my wanted behavior.

What am I doing wrong?

Are you using a template in a card that does not support templates?