Spanish translations not working

Steps to reproduce:

• Create a Custom document type called Client, with a schema with 3 fields:
  • name (String)
  • surname (String)
  • gender (Directory)
• Create the translations for each field
  messages.json

  {
  	"label.document.type.client": "Client",
    
    "label.doctype.client.name": "Name",
    "label.doctype.client.surname": "Surname",
    "label.doctype.client.gender": "Gender"  
  }
  

{
	"label.document.type.client": "Cliente",
  
  "label.doctype.client.name": "Nombre",
  "label.doctype.client.surname": "Apellido",
  "label.doctype.client.gender": "Genero"  
}

{
	"label.document.type.client": "Cliente",
  
  "label.doctype.client.name": "Nombre",
  "label.doctype.client.surname": "Apellido",
  "label.doctype.client.gender": "Genero"  
}

• Use i18n method in the creation layout

  <!--
  `nuxeo-client-create-layout`
  @group Nuxeo UI
  @element nuxeo-client-create-layout
  -->
  <dom-module id="nuxeo-client-create-layout">
    <template>
      <style>
        *[role=widget] {
          padding: 5px;
        }
      </style>
      <nuxeo-input role="widget" value="{{document.properties.dc:title}}" label="[[i18n('title')]]" type="text"></nuxeo-input>
  
      <nuxeo-input role="widget" value="{{document.properties.dc:description}}" label="[[i18n('label.description')]]" type="text"></nuxeo-input>
  
      <nuxeo-directory-suggestion role="widget" value="{{document.properties.client:gender}}" label="[[i18n('label.doctype.client.gender')]]" directory-name="genders"></nuxeo-directory-suggestion>
  
      <nuxeo-input role="widget" value="{{document.properties.client:name}}" label="[[i18n('label.doctype.client.name')]]" type="text"></nuxeo-input>
  
      <nuxeo-input role="widget" value="{{document.properties.client:surname}}" label="[[i18n('label.doctype.client.surname')]]" type="text"></nuxeo-input>
  
    </template>
  
    <script>
    Polymer({
      is: 'nuxeo-client-create-layout',
      behaviors: [Nuxeo.LayoutBehavior],
      properties: {
  
        /**
           * @doctype Client
           */
        document: {
          type: Object,
        },
  
      }
    });
    </script>
  </dom-module>
  

• Deploy your changes

Default tranlation (messages.json) and french translation (messages-fr.json) are applyed, but spanish translations are not applyed (messages-es.json and/or messages-es_ES.json)