Entity-filter with "not in" state filter not working?

I want to list all the devices not in a certain zone (= that are not Home).
To do this I am using the entity-filter card, which has the option for a state_filter.

But I can not get the state_filter to work using "not in" for the Zones array (['Home'])

In developer tools:

{{ state_attr('sensor.iphone_one_geocoded_location','Zones') }} 
→ ['Home'] 

My card:

type: entity-filter
show_empty: false
entities:
  - entity: sensor.iphone_one_geocoded_location
    name: One
  - entity: sensor.iphone_two_geocoded_location
    name: Two
state_filter:
  - value: Home
    operator: "not in"
    attribute: Zones    
card:
  type: glance
  show_state: true
  show_icon: false
  title: Not home

This card is never shown (neither Home or Away entities are shown).
As a test, when I (incorrectly) replace “not in” with “!==” the card is shown with all entities (and in that case as expected ignoring the state_filter).

Suggestions?

Look in developer tools / states. Is the state of sensor.iphone_one_geocoded_locationHome’ or ‘home’?

The template editor results are interpreted, as are Lovelace states.

The state is the geocoded location (address string), the Zone attribute is indeed an array containing Home - with capital H). I see the same for that attribute in Developer Tools > States (but then as flat string: “Home”).

But my original message was unclear, because the issues seems to appear only if the Zones attribute is an empty array.
Having iphone_two with Zones ['Work'] works as expected, but iphone_two with Zones [] does not.

{{ state_attr('sensor.iphone_two_geocoded_location','Zones') }} 
→ []

With iphone_one ['Home'] and iphone_two ['Work'] it correctly shows iphone_two.
But iphone_two with Zones [] is not shown even though it should pass the same state_filter: does not contain Home.