pushtotalk.py fails after 2 successfull question/answer ( raspberry PI )

[jalmince]

When recording the third question, it does not react anymore

Here is the output of "python3 pushtotalk.py" :

-- 2 times :
< Recording audio request.
Transcript of user request
End of audio request detected.
Stopping recording.
Playing assistant response.
Finished playing assistant response. > so it has worked fine

and from then on, when I ask a third the request :

INFO:root:Recording audio request.
ERROR:grpc._cython.cygrpc:Invalid encoding on b'\xff\xff\xff\xffH]2\xb4\x00\x17\x08\x00X\xf3'
Traceback (most recent call last):
File "src/python/grpcio/grpc/_cython/_cygrpc/grpc_string.pyx.pxi", line 48, in grpc._cython.cygrpc._decode
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte
Traceback (most recent call last):
File "/home/pi/assistant-sdk-python/google-assistant-sdk/googlesamples/assistant/grpc/pushtotalk.py", line 460, in
main()
File "/home/pi/.local/lib/python3.9/site-packages/click/core.py", line 722, in call
return self.main(*args, **kwargs)
File "/home/pi/.local/lib/python3.9/site-packages/click/core.py", line 697, in main
rv = self.invoke(ctx)
File "/home/pi/.local/lib/python3.9/site-packages/click/core.py", line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/pi/.local/lib/python3.9/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/home/pi/assistant-sdk-python/google-assistant-sdk/googlesamples/assistant/grpc/pushtotalk.py", line 458, in main
assistant.assist()
File "/home/pi/.local/lib/python3.9/site-packages/tenacity/init.py", line 241, in wrapped_f
return self.call(f, *args, **kw)
File "/home/pi/.local/lib/python3.9/site-packages/tenacity/init.py", line 329, in call
do = self.iter(result=result, exc_info=exc_info,
File "/home/pi/.local/lib/python3.9/site-packages/tenacity/init.py", line 279, in iter
return fut.result()
File "/usr/lib/python3.9/concurrent/futures/_base.py", line 433, in result
return self.__get_result()
File "/usr/lib/python3.9/concurrent/futures/_base.py", line 389, in __get_result
raise self._exception
File "/home/pi/.local/lib/python3.9/site-packages/tenacity/init.py", line 333, in call
result = fn(*args, **kwargs)
File "/home/pi/assistant-sdk-python/google-assistant-sdk/googlesamples/assistant/grpc/pushtotalk.py", line 138, in assist
for resp in self.assistant.Assist(iter_log_assist_requests(),
File "/home/pi/.local/lib/python3.9/site-packages/grpc/_channel.py", line 426, in next
return self._next()
File "/home/pi/.local/lib/python3.9/site-packages/grpc/_channel.py", line 826, in _next
raise self
grpc._channel._MultiThreadedRendezvous: <_MultiThreadedRendezvous of RPC that terminated with:
status = StatusCode.UNKNOWN
details = "ÿÿÿÿH]2Xó"
debug_error_string = "{"created":"@1643310220.215581629","description":"Error received from peer ipv4:172.217.168.42:443","file":"src/core/lib/surface/call.cc","file_line":1074,"grpc_message":"Unknown Error.","grpc_status":2}"

Expression 'alsa_snd_pcm_mmap_begin( self->pcm, &areas, &self->offset, numFrames )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 3994
Expression 'PaAlsaStreamComponent_RegisterChannels( &self->capture, &self->bufferProcessor, &captureFrames, &xrun )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 4108
Expression 'PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 4437

Could someone kindly help ?

best,
Jean-Paul