eZ Platform - Symfony language is always "en" even when I change the current site access

ezplatform.yml

imports:
    - { resource: image_variations.yml }
    - { resource: views.yml }

ezpublish:

    locale_conversion:
        eng-GB: en_GB
        fre-FR: fr_FR
        esp-ES: es_ES

    # HttpCache settings, By default 'local' (Symfony HttpCache Proxy), by setting it to 'http' you can point it to Varnish
    http_cache:
        purge_type: '%purge_type%'

    # Repositories configuration, setup default repository to support solr if enabled
    repositories:
        default:
            storage: ~
            search:
                engine: '%search_engine%'
                connection: default

    # Siteaccess configuration, with one siteaccess per default
    siteaccess:
        list: [en, fr, es, admin]
        groups:
            site_group: [en, fr, es]

            # WARNING: Do not remove or rename this group.
            # It's used to distinguish common siteaccesses from admin ones.
            # In case of multisite with multiple admin panels, remember to add any additional admin siteaccess to this group.
            admin_group: [admin]
        default_siteaccess: en
        match:
            URIElement: 1

    # System settings, grouped by siteaccess and/or siteaccess group
    system:
        site_group:
            # Cache pool service, needs to be different per repository (database) on multi repository install.
            cache_service_name: '%cache_pool%'
            # These reflect the current installers, complete installation before you change them. For changing var_dir
            # it is recommended to install clean, then change setting before you start adding binary content, otherwise you'll
            # need to manually modify your database data to reflect this to avoid exceptions.
            var_dir: var/site
            # System languages. Note that by default, content, content types, and other data are in eng-GB locale,
            # so removing eng-GB from this list may lead to errors or content not being shown, unless you change
            # all eng-GB data to other locales first.
            languages: [eng-GB, fre-FR, esp-ES]
            content:
                # As we by default enable EzSystemsPlatformHttpCacheBundle which is designed to expire all affected cache
                # on changes, and as error / redirects now have separate ttl, we easier allow ttl to be greatly increased
                default_ttl: '%httpcache_default_ttl%'
            # HttpCache purge server(s) setting, eg Varnish, for when ezpublish.http_cache.purge_type is set to 'http'.
            http_cache:
                purge_servers: ['%purge_server%']

            user_content_type_identifier: ['spaceobs_user']
            translation_siteaccesses: [en, fr, es]
            design: main
        en:
            #cache_service_name: '%cache_pool%'
            languages: [eng-GB, fre-FR, esp-ES]
        fr:
            #cache_service_name: '%cache_pool%'
            languages: [fre-FR, eng-GB]
        es:
            #cache_service_name: '%cache_pool%'
            languages: [esp-ES, eng-GB]
        # WARNING: Do not remove or rename this group.
        admin_group:
            cache_service_name: '%cache_pool%'
            var_dir: var/site
            languages: [eng-GB]
            content:
                default_ttl: '%httpcache_default_ttl%'
            http_cache:
                purge_servers: ['%purge_server%']
            design: admin
    url_alias:
        slug_converter:
            transformation: 'urlalias_lowercase'

ezdesign:
    design_list:
        main: [spobsremote]
        admin: [admin, spobsremote]

ez_platform_standard_design:
    # makes Kernel default templates (in EzPublishCoreBundle/Resources/views) part of standard Design
    override_kernel_templates: false