Dialogflow follow-up

1

I’ve set-up intents in dialogflow. These intents have follow-up intents that pose me a series of questions.
Each question holds a variable that is passed to the next intent.

The values are passed correctly to home assistant, as I conclude from the json:

"contexts": [
      {
        "name": "afwezig_tijdstip-followup",
        "parameters": {
          "time.original": "20u",
          "time": "20:00:00"
        },
        "lifespan": 1
      }
    ],

My intents configuration holds:

{{ afwezig_tijdstip-followup.time }}

as a variable passed from dialogflow.

Problem is that Home Assistant seems to have a problem with this, since the response I get is the following:

{
  "speech": "Error handling intent.",
  "source": "Home Assistant Dialogflow",
  "displayText": "Error handling intent."
}

What am I missing here?