How to configure Page Manager variants based on Domain module?

I've inherited a Drupal 8 website that must be upgraded to Drupal 9. The site has several subdomains declared, using Domain module.

Some pages are build with Page Manager, having 2 variants based on a domain selection criteria basis:

• Variant "A" should be selected when the domain is www.example.com. I.e.: www.example.com/example-page
• Variant "B" should be selected when the domain is NOT www.example.com. I.e.: subdomain1.example.com/example-page

I can confirm that this behavior worked in Drupal 8.9, prior to upgrade to Drupal 9. However, now I can't set a selection criteria based on a domain in the UI. I've forced it overriding the config yaml by adding a domain rule on the selection_criteria key, but I don't know if I did it properly. This is an example:

page_manager.page_variant.example-block_display-1.yml

uuid: ad75cd71-ab2f-42af-92d1-599824223224
langcode: 
status: true
dependencies:
  config:
    - page_manager.page.example
    - views.view.example
  module:
    - system
    - views
    - domain
id: example-block_display-1
label: 'Variant 1'
weight: 0
variant: block_display
variant_settings:
  id: block_display
  label: null
  weight: 0
  uuid: d23c2a50-17c7-4777-a419-c7c2200fc9f9
  blocks:
    dd22957b-c81d-43f3-bb28-c209f17db480:
      id: 'views_block:example-example'
      label: ''
      label_display: '0'
      provider: views
      context_mapping: {  }
      views_label: ''
      items_per_page: none
      exposed: {  }
      region: top
      weight: 0
      uuid: dd22957b-c81d-43f3-bb28-c209f22db480
  page_title: 'Variant 1 page title'
page: example
selection_criteria:
  1:
    id: domain
    negate: true
    context_mapping: {  }
    www_example: www_example
selection_logic: and
static_context: {  }

page_manager.page_variant.example-block_display-2.yml

uuid: ad75cd71-ab2f-42af-92d1-599124223224
langcode: 
status: true
dependencies:
  config:
    - page_manager.page.example
    - views.view.example
  module:
    - system
    - views
    - domain
id: example-block_display-2
label: 'Variant 2'
weight: 0
variant: block_display
variant_settings:
  id: block_display
  label: null
  weight: 0
  uuid: d23c2a50-17c7-4777-a419-c7c1100fc9f9
  blocks:
    dd22957b-c81d-43f3-bb28-c209f17db480:
      id: 'views_block:example-example'
      label: ''
      label_display: '0'
      provider: views
      context_mapping: {  }
      views_label: ''
      items_per_page: none
      exposed: {  }
      region: top
      weight: 0
      uuid: dd22957b-c81d-43f3-bb28-c209112db480
  page_title: 'Variant 2 page title'
page: example
selection_criteria:
  1:
    id: domain
    negate: false
    context_mapping: {  }
    www_example: www_example
selection_logic: and
static_context: {  }

Any idea to get it working?

I've installed these modules:

• drupal/domain: "^1.0@beta"
• drupal/domain_config: "^1@alpha"
• drupal/domain_site_settings: "^1.4"
• drupal/page_manager: "^4.0@RC"

I'm currently using Drupal 9.5.9, PHP 8.1.16 and MariaDB 10.5.19

Any help would very appreciated.