DNS resolution failed for service: embeddedassistant.googleapis.com

[dony71]

run "python -m pushtotalk -v" has error below
no problem ping and curl to embeddedassistant.googleapis.com
any idea what's wrong?

DEBUG:google.auth.transport.requests:Making request: POST https://accounts.google.com/o/oauth2/token
DEBUG:urllib3.connectionpool:Starting new HTTPS connection (1): accounts.google.com:443
DEBUG:urllib3.connectionpool:https://accounts.google.com:443 "POST /o/oauth2/token HTTP/1.1" 200 None
INFO:root:Connecting to embeddedassistant.googleapis.com
INFO:root:Using device model raspi--assistant-a0136-raspi-google-assistant-t5vhpv and device id 3286bef6-73ee-11ec-ab5c-7dc9ed6e3fdb
Press Enter to send a new request...
INFO:root:Recording audio request.
DEBUG:root:AssistRequest: config {
  audio_in_config {
    encoding: LINEAR16
    sample_rate_hertz: 16000
  }
  audio_out_config {
    encoding: LINEAR16
    sample_rate_hertz: 16000
    volume_percentage: 50
  }
  dialog_state_in {
    language_code: "en-US"
    is_new_conversation: true
  }
  device_config {
    device_id: "3286bef6-73ee-11ec-ab5c-7dc9ed6e3fdb"
    device_model_id: "raspi--assistant-a0136-raspi-google-assistant-t5vhpv"
  }
}

ERROR:root:grpc unavailable error: <_MultiThreadedRendezvous of RPC that terminated with:
        status = StatusCode.UNAVAILABLE
        details = "DNS resolution failed for service: embeddedassistant.googleapis.com"
        debug_error_string = "{"created":"@1642027159.438547980","description":"Resolver transient failure","file":"src/core/ext/filters/client_channel/client_channel.cc","file_line":1324,"referenced_errors":[{"created":"@1642027159.438541240","description":"DNS resolution failed for service: embeddedassistant.googleapis.com","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc","file_line":359,"grpc_status":14,"referenced_errors":[{"created":"@1642027159.438415759","description":"C-ares status is not ARES_SUCCESS qtype=A name=embeddedassistant.googleapis.com is_balancer=0: Timeout while contacting DNS servers","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc","file_line":698,"referenced_errors":[{"created":"@1642027159.438403296","description":"C-ares status is not ARES_SUCCESS qtype=AAAA name=embeddedassistant.googleapis.com is_balancer=0: Timeout while contacting DNS servers","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc","file_line":698}]}]}]}"
>
INFO:root:Recording audio request.
DEBUG:root:AssistRequest: config {
  audio_in_config {
    encoding: LINEAR16
    sample_rate_hertz: 16000
  }
  audio_out_config {
    encoding: LINEAR16
    sample_rate_hertz: 16000
    volume_percentage: 50
  }
  dialog_state_in {
    language_code: "en-US"
  }
  device_config {
    device_id: "3286bef6-73ee-11ec-ab5c-7dc9ed6e3fdb"
    device_model_id: "raspi--assistant-a0136-raspi-google-assistant-t5vhpv"
  }
}

ERROR:root:grpc unavailable error: <_MultiThreadedRendezvous of RPC that terminated with:
        status = StatusCode.UNAVAILABLE
        details = "DNS resolution failed for service: embeddedassistant.googleapis.com"
        debug_error_string = "{"created":"@1642027159.438547980","description":"Resolver transient failure","file":"src/core/ext/filters/client_channel/client_channel.cc","file_line":1324,"referenced_errors":[{"created":"@1642027159.438541240","description":"DNS resolution failed for service: embeddedassistant.googleapis.com","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc","file_line":359,"grpc_status":14,"referenced_errors":[{"created":"@1642027159.438415759","description":"C-ares status is not ARES_SUCCESS qtype=A name=embeddedassistant.googleapis.com is_balancer=0: Timeout while contacting DNS servers","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc","file_line":698,"referenced_errors":[{"created":"@1642027159.438403296","description":"C-ares status is not ARES_SUCCESS qtype=AAAA name=embeddedassistant.googleapis.com is_balancer=0: Timeout while contacting DNS servers","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc","file_line":698}]}]}]}"
>
INFO:root:Recording audio request.
DEBUG:root:AssistRequest: config {
  audio_in_config {
    encoding: LINEAR16
    sample_rate_hertz: 16000
  }
  audio_out_config {
    encoding: LINEAR16
    sample_rate_hertz: 16000
    volume_percentage: 50
  }
  dialog_state_in {
    language_code: "en-US"
  }
  device_config {
    device_id: "3286bef6-73ee-11ec-ab5c-7dc9ed6e3fdb"
    device_model_id: "raspi--assistant-a0136-raspi-google-assistant-t5vhpv"
  }
}

ERROR:root:grpc unavailable error: <_MultiThreadedRendezvous of RPC that terminated with:
        status = StatusCode.UNAVAILABLE
        details = "DNS resolution failed for service: embeddedassistant.googleapis.com"
        debug_error_string = "{"created":"@1642027159.438547980","description":"Resolver transient failure","file":"src/core/ext/filters/client_channel/client_channel.cc","file_line":1324,"referenced_errors":[{"created":"@1642027159.438541240","description":"DNS resolution failed for service: embeddedassistant.googleapis.com","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc","file_line":359,"grpc_status":14,"referenced_errors":[{"created":"@1642027159.438415759","description":"C-ares status is not ARES_SUCCESS qtype=A name=embeddedassistant.googleapis.com is_balancer=0: Timeout while contacting DNS servers","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc","file_line":698,"referenced_errors":[{"created":"@1642027159.438403296","description":"C-ares status is not ARES_SUCCESS qtype=AAAA name=embeddedassistant.googleapis.com is_balancer=0: Timeout while contacting DNS servers","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc","file_line":698}]}]}]}"
>
Traceback (most recent call last):
  File "/usr/lib/python3.8/runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/usr/lib/python3.8/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/srv/googleassistant/lib/python3.8/site-packages/googlesamples/assistant/grpc/pushtotalk.py", line 469, in <module>
    main()
  File "/srv/googleassistant/lib/python3.8/site-packages/click/core.py", line 722, in __call__
    return self.main(*args, **kwargs)
  File "/srv/googleassistant/lib/python3.8/site-packages/click/core.py", line 697, in main
    rv = self.invoke(ctx)
  File "/srv/googleassistant/lib/python3.8/site-packages/click/core.py", line 895, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/srv/googleassistant/lib/python3.8/site-packages/click/core.py", line 535, in invoke
    return callback(*args, **kwargs)
  File "/srv/googleassistant/lib/python3.8/site-packages/googlesamples/assistant/grpc/pushtotalk.py", line 458, in main
    continue_conversation = assistant.assist()
  File "/srv/googleassistant/lib/python3.8/site-packages/tenacity/__init__.py", line 241, in wrapped_f
    return self.call(f, *args, **kw)
  File "/srv/googleassistant/lib/python3.8/site-packages/tenacity/__init__.py", line 329, in call
    do = self.iter(result=result, exc_info=exc_info,
  File "/srv/googleassistant/lib/python3.8/site-packages/tenacity/__init__.py", line 297, in iter
    raise retry_exc.reraise()
  File "/srv/googleassistant/lib/python3.8/site-packages/tenacity/__init__.py", line 136, in reraise
    raise self.last_attempt.result()
  File "/usr/lib/python3.8/concurrent/futures/_base.py", line 437, in result
    return self.__get_result()
  File "/usr/lib/python3.8/concurrent/futures/_base.py", line 389, in __get_result
    raise self._exception
  File "/srv/googleassistant/lib/python3.8/site-packages/tenacity/__init__.py", line 333, in call
    result = fn(*args, **kwargs)
  File "/srv/googleassistant/lib/python3.8/site-packages/googlesamples/assistant/grpc/pushtotalk.py", line 138, in assist
    for resp in self.assistant.Assist(iter_log_assist_requests(),
  File "/srv/googleassistant/lib/python3.8/site-packages/grpc/_channel.py", line 426, in __next__
    return self._next()
  File "/srv/googleassistant/lib/python3.8/site-packages/grpc/_channel.py", line 809, in _next
    raise self
grpc._channel._MultiThreadedRendezvous: <_MultiThreadedRendezvous of RPC that terminated with:
        status = StatusCode.UNAVAILABLE
        details = "DNS resolution failed for service: embeddedassistant.googleapis.com"
        debug_error_string = "{"created":"@1642027159.438547980","description":"Resolver transient failure","file":"src/core/ext/filters/client_channel/client_channel.cc","file_line":1324,"referenced_errors":[{"created":"@1642027159.438541240","description":"DNS resolution failed for service: embeddedassistant.googleapis.com","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc","file_line":359,"grpc_status":14,"referenced_errors":[{"created":"@1642027159.438415759","description":"C-ares status is not ARES_SUCCESS qtype=A name=embeddedassistant.googleapis.com is_balancer=0: Timeout while contacting DNS servers","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc","file_line":698,"referenced_errors":[{"created":"@1642027159.438403296","description":"C-ares status is not ARES_SUCCESS qtype=AAAA name=embeddedassistant.googleapis.com is_balancer=0: Timeout while contacting DNS servers","file":"src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc","file_line":698}]}]}]}"