title: How to fix "it doesn't support that" when I query Alexa retrievable property
body: <p>I have this endpoint with powerState and connectivity properties both retrievable:</p>
  
  <pre><code>    {
          "endpointId": "123",
          "manufacturerName": "abc",
          "friendlyName": "lamp",
          "description": "lamp",
          "displayCategories": [
              "LIGHT"
          ],
          "capabilities": [
              {
                  "type": "AlexaInterface",
                  "interface": "Alexa.PowerController",
                  "version": "3",
                  "properties": {
                      "supported": [{
                              "name": "powerState"
                          }],
                      "retrievable": true
                  }
              },
              {
                  "type": "AlexaInterface",
                  "interface": "Alexa.EndpointHealth",
                  "version": "3",
                  "properties": {
                      "supported": [{
                              "name": "connectivity"
                          }],
                      "retrievable": true
                  }
              }
          ],
          "cookie": {}
      }
  
  </code></pre>
  
  <p>I respond to ReportState request by sending the state of both properties:</p>
  
  <pre><code>
      {
          "context": {
              "properties": [
                  {
                      "namespace": "Alexa.PowerController",
                      "name": "powerState",
                      "value": "ON",
                      "timeOfSample": "2019-01-10T10:17:19.99Z",
                      "uncertaintyInMilliseconds": 50
                  },
                  {
                      "namespace": "Alexa.EndpointHealth",
                      "name": "connectivity",
                      "value": {
                          "value": "OK"
                      },
                      "timeOfSample": "2019-01-10T10:17:19.90Z",
                      "uncertaintyInMilliseconds": 50
                  }
              ]
          },
          "event": {
              "header": {
                  "namespace": "Alexa",
                  "name": "StateReport",
                  "payloadVersion": "3",
                  "messageId": "cde",
                  "correlationToken": "efg123"
              },
              "endpoint": {
                  "scope": {
                      "type": "BearerToken",
                      "token": "ab123"
                  },
                  "endpointId": "123",
                  "cookie": {}
              },
              "payload": {}
          }
      }
  
  </code></pre>
  
  <p>And I send the same context in the PowerController response.
  In the Alexa app I can see my device, turn it on and off and view its state rightly. I can ask Alexa to turn on and off my device and the response in "OK", but if I try to ask:** "Is my device turned on?" ** Alexa answers that <strong>this device doesn't support that</strong>.</p>
  
  <p>The skill language is Italian and PowerController documentation <a href="https://developer.amazon.com/it/docs/device-apis/alexa-powercontroller.html" rel="nofollow noreferrer">https://developer.amazon.com/it/docs/device-apis/alexa-powercontroller.html</a> says that query is supported.</p>
  
  <p>What am I missing?</p>