lovelace-card-mod: 'if config.entity is none' template doesn't work

My Home Assistant version: 2021.6.6

My lovelace configuration method (GUI or yaml): YAML What I am doing:

trying to have a conditional badge, templating on existence of the config.entity

  - entity: sensor.state_badge
    card_mod:
      style: |
        :host {
          display: {% if config.entity is none %}none{%endif%}
        }

Also tried {% if not config.entity %} and {% if config.entity not is defined %}

What I expected to happen:

don’t display the badge if the entity doesn’t exist (yet)

What happened instead:

Minimal steps to reproduce:

# The least amount of code possible to reproduce my error
  - entity: sensor.state_badge
    card_mod:
      style: |
        :host {
          display: {% if config.entity is none %}none{%endif%}
        }

# End of code

Error messages from the browser console:

Unhandled Promise Rejection: TypeError: null is not an object (evaluating 'this.shadowRoot.querySelector')

---

though the above error also shows on correct badges, and I have reported that in another issue

please also see a community post.

as an example:

    card_mod:
      style: |
        :host {
          display: {% if states('binary_sensor.updater') == 'off' %} none {% endif %}
        }

works perfectly.

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