Regular crashes of Home Assistant Core

I have rather regular crashed (roughly weekly) of my instance of Home Assistant.
It has been the case for a few months now. It occurs on all releases 0.1xx and and all type of setup: Generic Install on Linux (debian), hassos, and now Home Assistant Core on Docker.
In every case the scenario looks similar in the log:

2020-06-11 17:10:45 ERROR (MainThread) [homeassistant.components.rest.switch] Timed out while fetching data
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/rest/switch.py", line 210, in get_device_state
    self._resource, auth=self._auth, headers=self._headers
  File "/usr/local/lib/python3.7/site-packages/aiohttp/client.py", line 483, in _request
    timeout=real_timeout
  File "/usr/local/lib/python3.7/site-packages/aiohttp/connector.py", line 523, in connect
    proto = await self._create_connection(req, traces, timeout)
  File "/usr/local/lib/python3.7/site-packages/aiohttp/connector.py", line 859, in _create_connection
    req, traces, timeout)
  File "/usr/local/lib/python3.7/site-packages/aiohttp/connector.py", line 986, in _create_direct_connection
    req=req, client_error=client_error)
  File "/usr/local/lib/python3.7/site-packages/aiohttp/connector.py", line 936, in _wrap_create_connection
    return await self._loop.create_connection(*args, **kwargs)  # type: ignore  # noqa
  File "/usr/local/lib/python3.7/asyncio/base_events.py", line 949, in create_connection
    await self.sock_connect(sock, address)
  File "/usr/local/lib/python3.7/asyncio/selector_events.py", line 473, in sock_connect
    return await fut
concurrent.futures._base.CancelledError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/rest/switch.py", line 198, in async_update
    await self.get_device_state(self.hass)
  File "/usr/src/homeassistant/homeassistant/components/rest/switch.py", line 212, in get_device_state
    text = await req.text()
  File "/usr/local/lib/python3.7/site-packages/async_timeout/__init__.py", line 45, in __exit__
    self._do_exit(exc_type)
  File "/usr/local/lib/python3.7/site-packages/async_timeout/__init__.py", line 92, in _do_exit
    raise asyncio.TimeoutError
concurrent.futures._base.TimeoutError
2020-06-11 17:10:45 ERROR (MainThread) [homeassistant.components.rest.switch] Timed out while fetching data
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/rest/switch.py", line 210, in get_device_state
    self._resource, auth=self._auth, headers=self._headers
  File "/usr/local/lib/python3.7/site-packages/aiohttp/client.py", line 483, in _request
    timeout=real_timeout
  File "/usr/local/lib/python3.7/site-packages/aiohttp/connector.py", line 523, in connect
    proto = await self._create_connection(req, traces, timeout)
  File "/usr/local/lib/python3.7/site-packages/aiohttp/connector.py", line 859, in _create_connection
    req, traces, timeout)
  File "/usr/local/lib/python3.7/site-packages/aiohttp/connector.py", line 986, in _create_direct_connection
    req=req, client_error=client_error)
  File "/usr/local/lib/python3.7/site-packages/aiohttp/connector.py", line 936, in _wrap_create_connection
    return await self._loop.create_connection(*args, **kwargs)  # type: ignore  # noqa
  File "/usr/local/lib/python3.7/asyncio/base_events.py", line 949, in create_connection
    await self.sock_connect(sock, address)
  File "/usr/local/lib/python3.7/asyncio/selector_events.py", line 473, in sock_connect
    return await fut
concurrent.futures._base.CancelledError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/rest/switch.py", line 198, in async_update
    await self.get_device_state(self.hass)
  File "/usr/src/homeassistant/homeassistant/components/rest/switch.py", line 212, in get_device_state
    text = await req.text()
  File "/usr/local/lib/python3.7/site-packages/async_timeout/__init__.py", line 45, in __exit__
    self._do_exit(exc_type)
  File "/usr/local/lib/python3.7/site-packages/async_timeout/__init__.py", line 92, in _do_exit
    raise asyncio.TimeoutError
concurrent.futures._base.TimeoutError
2020-06-11 17:10:46 ERROR (MainThread) [homeassistant.helpers.entity] Update for camera.exterieur fails
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/urllib3/connection.py", line 160, in _new_conn
    (self._dns_host, self.port), self.timeout, **extra_kw
  File "/usr/local/lib/python3.7/site-packages/urllib3/util/connection.py", line 84, in create_connection
    raise err
  File "/usr/local/lib/python3.7/site-packages/urllib3/util/connection.py", line 74, in create_connection
    sock.connect(sa)
socket.timeout: timed out

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/urllib3/connectionpool.py", line 677, in urlopen
    chunked=chunked,
  File "/usr/local/lib/python3.7/site-packages/urllib3/connectionpool.py", line 392, in _make_request
    conn.request(method, url, **httplib_request_kw)
  File "/usr/local/lib/python3.7/http/client.py", line 1252, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/usr/local/lib/python3.7/http/client.py", line 1298, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/usr/local/lib/python3.7/http/client.py", line 1247, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/usr/local/lib/python3.7/http/client.py", line 1026, in _send_output
    self.send(msg)
  File "/usr/local/lib/python3.7/http/client.py", line 966, in send
    self.connect()
  File "/usr/local/lib/python3.7/site-packages/urllib3/connection.py", line 187, in connect
    conn = self._new_conn()
  File "/usr/local/lib/python3.7/site-packages/urllib3/connection.py", line 167, in _new_conn
    % (self.host, self.timeout),
urllib3.exceptions.ConnectTimeoutError: (<urllib3.connection.HTTPConnection object at 0x7fa573e46910>, 'Connection to 10.1.0.90 timed out. (connect timeout=5)')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/requests/adapters.py", line 449, in send
    timeout=timeout
  File "/usr/local/lib/python3.7/site-packages/urllib3/connectionpool.py", line 725, in urlopen
    method, url, error=e, _pool=self, _stacktrace=sys.exc_info()[2]
  File "/usr/local/lib/python3.7/site-packages/urllib3/util/retry.py", line 439, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPConnectionPool(host='10.1.0.90', port=5000): Max retries exceeded with url: /webapi/entry.cgi?_sid=OuGs8iQHiUhoTHGwi1SbeOPhjxwVZii8wLFWa-EuIgowVmsY4uIxkMZ_MugUg48XYQR_SQ8vVDj_dLjjUVmwDo&api=SYNO.SurveillanceStation.Camera&method=List&version=1 (Caused by ConnectTimeoutError(<urllib3.connection.HTTPConnection object at 0x7fa573e46910>, 'Connection to 10.1.0.90 timed out. (connect timeout=5)'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 279, in async_update_ha_state
    await self.async_device_update()
  File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 472, in async_device_update
    await self.hass.async_add_executor_job(self.update)
  File "/usr/local/lib/python3.7/concurrent/futures/thread.py", line 57, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/src/homeassistant/homeassistant/components/synology/camera.py", line 118, in update
    self._surveillance.update()
  File "/usr/local/lib/python3.7/site-packages/synology/surveillance_station.py", line 20, in update
    cameras = self._api.camera_list()
  File "/usr/local/lib/python3.7/site-packages/synology/api.py", line 101, in camera_list
    response = self._get_json_with_retry(api['url'], payload)
  File "/usr/local/lib/python3.7/site-packages/synology/api.py", line 192, in _get_json_with_retry
    return self._get_json(url, payload)
  File "/usr/local/lib/python3.7/site-packages/synology/api.py", line 198, in _get_json
    response = self._get(url, payload)
  File "/usr/local/lib/python3.7/site-packages/synology/api.py", line 185, in _get
    verify=self._verify_ssl)
  File "/usr/local/lib/python3.7/site-packages/requests/api.py", line 76, in get
    return request('get', url, params=params, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/requests/api.py", line 61, in request
    return session.request(method=method, url=url, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/requests/sessions.py", line 530, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/local/lib/python3.7/site-packages/requests/sessions.py", line 643, in send
    r = adapter.send(request, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/requests/adapters.py", line 504, in send
    raise ConnectTimeout(e, request=request)
requests.exceptions.ConnectTimeout: HTTPConnectionPool(host='10.1.0.90', port=5000): Max retries exceeded with url: /webapi/entry.cgi?_sid=OuGs8iQHiUhoTHGwi1SbeOPhjxwVZii8wLFWa-EuIgowVmsY4uIxkMZ_MugUg48XYQR_SQ8vVDj_dLjjUVmwDo&api=SYNO.SurveillanceStation.Camera&method=List&version=1 (Caused by ConnectTimeoutError(<urllib3.connection.HTTPConnection object at 0x7fa573e46910>, 'Connection to 10.1.0.90 timed out. (connect timeout=5)'))
2020-06-11 17:10:52 INFO (SyncWorker_4) [googleapiclient.discovery] URL being requested: GET https://www.googleapis.com/discovery/v1/apis/calendar/v3/rest
2020-06-11 17:10:52 ERROR (SyncWorker_9) [homeassistant.components.yeelight] Unable to update device 10.1.0.15, YeelightPlacard: Bulb closed the connection.
2020-06-11 17:10:52 ERROR (SyncWorker_9) [homeassistant.components.yeelight] Unable to update device 10.1.0.11, Yeelight: Bulb closed the connection.
2020-06-11 17:10:52 ERROR (SyncWorker_9) [homeassistant.components.yeelight] Unable to update device 10.1.0.158, Strip1: Bulb closed the connection.
2020-06-11 17:10:52 ERROR (SyncWorker_9) [homeassistant.components.yeelight] Unable to update device 10.1.0.51, Strip2: Bulb closed the connection.
2020-06-11 17:10:52 ERROR (SyncWorker_9) [homeassistant.components.yeelight] Unable to update device 10.1.0.60, Strip3: Bulb closed the connection.
2020-06-11 17:10:52 INFO (SyncWorker_4) [googleapiclient.discovery] URL being requested: GET https://www.googleapis.com/calendar/v3/calendars/s5lbp7v3e6rmjla04fi1oq3vf8%40group.calendar.google.com/events?orderBy=startTime&maxResults=5&singleEvents=true&timeMin=2020-06-11T19%3A10%3A52.105970%2B02%3A00&alt=json
2020-06-11 17:10:52 ERROR (SyncWorker_9) [homeassistant.components.yeelight] Unable to update device 10.1.0.34, Strip4: Bulb closed the connection.2020-06-11 17:10:52 INFO (SyncWorker_13) [googleapiclient.discovery] URL being requested: GET https://www.googleapis.com/calendar/v3/calendars/ima8u8rgbhtdrdlovt356ttik8%40group.calendar.google.com/events?orderBy=startTime&maxResults=5&singleEvents=true&timeMin=2020-06-11T19%3A10%3A52.343140%2B02%3A00&alt=json
2020-06-11 17:11:35 ERROR (MainThread) [homeassistant.components.mqtt.climate] Could not parse temperature from unavailable
2020-06-11 17:16:35 ERROR (MainThread) [homeassistant.components.mqtt.climate] Could not parse temperature from unavailable
2020-06-11 17:21:35 ERROR (MainThread) [homeassistant.components.mqtt.climate] Could not parse temperature from unavailable
2020-06-11 17:26:05 INFO (SyncWorker_13) [oauth2client.transport] Refreshing due to a 401 (attempt 1/2)
2020-06-11 17:26:35 ERROR (MainThread) [homeassistant.components.mqtt.climate] Could not parse temperature from unavailable
2020-06-11 17:29:39 ERROR (MainThread) [homeassistant.components.websocket_api.http.connection.140348548613840] Unable to serialize to JSON. Bad data found at $.result[72](state: climate.migo).attributes.temperature=nan(<class 'float'>

Timeout on fetching data… and then a serie of exceptions and eventually, game over.

On every crash it seems that there is something wrong with the Synology Camera integration:

requests.exceptions.ConnectTimeout: HTTPConnectionPool(host='10.1.0.90', port=5000): Max retries exceeded with url: /webapi/entry.cgi?_sid=OuGs8iQHiUhoTHGwi1SbeOPhjxwVZii8wLFWa-EuIgowVmsY4uIxkMZ_MugUg48XYQR_SQ8vVDj_dLjjUVmwDo&api=SYNO.SurveillanceStation.Camera&method=List&version=1 (Caused by ConnectTimeoutError(<urllib3.connection.HTTPConnection object at 0x7fa573e46910>, 'Connection to 10.1.0.90 timed out. (connect timeout=5)'))

My LAN is very stable and there is no obvious reason for the connexion between HA and my synology box to fail.

Any hints on understanding what is going on?

Thanks,

GV