Google Assistant - Home-App Error on connection

Hi,

I´ve done all steps in this tutorial:
Google Assistant integration

My instance is accessible from the Internet (IPv4 and IPv6) with an SSL certificate.

When I integrate my [test] into the Home app, I can log in to my Home Assistant, but shortly afterwards I get a “connection error”.

I’m stuck and need help.

Greets

When I push Synchronize on Home Assistant:
Need help!

Unable to sync devices with result code: 404, check log for more info.
Log:
2024-10-21 14:51:06.858 ERROR (MainThread) [homeassistant.components.google_assistant.http] Request for https://homegraph.googleapis.com/v1/devices:requestSync failed: 404
2024-10-21 14:51:06.859 ERROR (MainThread) [homeassistant.components.websocket_api.http.connection] [138945279630000] Unexpected exception
Traceback (most recent call last):
File “/usr/src/homeassistant/homeassistant/components/websocket_api/commands.py”, line 245, in handle_call_service
response = await hass.services.async_call(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/src/homeassistant/homeassistant/core.py”, line 2761, in async_call
response_data = await coro
^^^^^^^^^^
File “/usr/src/homeassistant/homeassistant/core.py”, line 2804, in _execute_service
return await target(service_call)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/src/homeassistant/homeassistant/helpers/service.py”, line 996, in entity_service_call
single_response = await _handle_entity_call(
^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/usr/src/homeassistant/homeassistant/helpers/service.py”, line 1068, in _handle_entity_call
result = await task
^^^^^^^^^^
File “/usr/src/homeassistant/homeassistant/components/button/init.py”, line 132, in _async_press_action
await self.async_press()
File “/usr/src/homeassistant/homeassistant/components/google_assistant/button.py”, line 60, in async_press
raise HomeAssistantError(
homeassistant.exceptions.HomeAssistantError: Unable to sync devices with result code: 404, check log for more info.

Error found, IPv4 → IPv6 was not running.

fixed it