Google Assistant through Nabu Casa

So I’ve been trying to get this to work, all devices do show up in Google Assistant, but trying to manually ‘flip’ a switch in Assistant app always gives me an error.

From the log this shows up:

Error handling message {'inputs': [{'context': {'locale_language': 'en'}, 'intent': 'action.devices.EXECUTE', 'payload': {'commands': [{'devices': [{'id': 'switch.newkaku_013b4c3e_2'}], 'execution': [{'command': 'action.devices.commands.OnOff', 'params': {'on': True}}]}]}}], 'requestId': '15098695497925521168'}: {'errorCode': 'unknownError'}

Anyone who can figure out whats going on?

As far as I understand it, I shouldn’t need to open any ports in my FW as long as I use Nabu Casa cloud feature.

[edit]
An error in the log I also noticed, could it be related?!

Traceback (most recent call last):
  File "/srv/homeassistant/lib/python3.7/site-packages/homeassistant/components/google_assistant/smart_home.py", line 55, in _process
    result = await handler(hass, data, inputs[0].get('payload'))
  File "/srv/homeassistant/lib/python3.7/site-packages/homeassistant/components/google_assistant/smart_home.py", line 180, in handle_devices_execute
    await entities[entity_id].execute(data, execution)
  File "/srv/homeassistant/lib/python3.7/site-packages/homeassistant/components/google_assistant/helpers.py", line 186, in execute
    await trt.execute(command, data, params, challenge)
  File "/srv/homeassistant/lib/python3.7/site-packages/homeassistant/components/google_assistant/trait.py", line 269, in execute
    }, blocking=True, context=data.context)
  File "/srv/homeassistant/lib/python3.7/site-packages/homeassistant/core.py", line 1141, in async_call
    self._execute_service(handler, service_call))
  File "/srv/homeassistant/lib/python3.7/site-packages/homeassistant/core.py", line 1163, in _execute_service
    await handler.func(service_call)
  File "/srv/homeassistant/lib/python3.7/site-packages/homeassistant/helpers/entity_component.py", line 194, in handle_service
    required_features
  File "/srv/homeassistant/lib/python3.7/site-packages/homeassistant/helpers/service.py", line 236, in entity_service_call
    raise UnknownUser(context=call.context)
homeassistant.exceptions.UnknownUser: UnknownUser