Active trail is cached incorrectly

We had this same issue. I was able to reproduce the issue with the below behat test, and with the patch in place the test is able to pass.

I'd recommend separating out layout builder concerns. They are possibly unrelated and shouldn't bog down what is a simple cache context fix.

Scenario: Active trail works on group menu and is cached correctly.
    Given group:
      | label            | type          | path              | status |
      | Behat test group | default_group | /behat-test-group | 1      |
    And I am logged in as a user with the "ohsu_contributor" role
    And I am a group member with the "senior_editor" role
    # Create a custom piece of content in the group with group menu.
    # @todo Replace with singular step.
    When I visit the form to create a "basic_page" in my group
    And I fill in "Title" with "Test menu 1"
    And I press the "Save" button
    # Below is equivelant to: And I check the box "Provide a menu link"
    And I check the box "field_group_content_menu_link[0][enabled]"
    And I fill in "Menu link title" with "Behat Test Gcontent Menu Link 1"
    And I fill in the meta description field as necessary
    And I press the "Add new content item" button
    Then I should see a created successfully message
    # Create ANOTHER custom piece of content in the group with group menu.
    # @todo Replace with singular step.
    When I visit the form to create a "basic_page" in my group
    And I fill in "Title" with "Test menu 2"
    And I press the "Save" button
    # Below is equivelant to: And I check the box "Provide a menu link"
    And I check the box "field_group_content_menu_link[0][enabled]"
    And I fill in "Menu link title" with "Behat Test Gcontent Menu Link 2"
    And I fill in the meta description field as necessary
    And I press the "Add new content item" button
    Then I should see a created successfully message
    # Confirm all links are in the group menu for the group.
    When I view the group with label "Behat test group"
    Then I should see the text "Behat Test Gcontent Menu Link 1" in the "group sidebar menu" region
    Then I should see the text "Behat Test Gcontent Menu Link 2" in the "group sidebar menu" region
    When I click "Behat Test Gcontent Menu Link 1" in the "group sidebar menu" region
    Then the ".nav-link.nav-link--active" element should contain "Behat Test Gcontent Menu Link 1"
    When I click "Behat Test Gcontent Menu Link 2" in the "group sidebar menu" region
    Then the ".nav-link.nav-link--active" element should contain "Behat Test Gcontent Menu Link 2"

Automatically closed - issue fixed for 2 weeks with no activity.