Same issue here, started with 2021.3.
Could not create snapshot at upgrade.
And when try to run manually, similar issue reported.
Usually nothing important is the logs, but as now try to do manually,
this now in Core log in red:
(and I can reach my HA cloud from my phone ‘outside’)
2021-03-06 17:50:02 ERROR (MainThread) [homeassistant.components.system_health] Error fetching system info for cloud - can_reach_cloud
Traceback (most recent call last):
File "/usr/src/homeassistant/homeassistant/components/system_health/__init__.py", line 212, in async_check_can_reach_url
await session.get(url, timeout=5)
File "/usr/local/lib/python3.8/site-packages/aiohttp/client.py", line 544, in _request
File "/usr/local/lib/python3.8/site-packages/aiohttp/client_reqrep.py", line 905, in start
self._continue = None
File "/usr/local/lib/python3.8/site-packages/aiohttp/helpers.py", line 656, in __exit__
raise asyncio.TimeoutError from None
2021-03-06 17:54:08 ERROR (MainThread) [homeassistant.components.hassio.handler] Timeout on /snapshots/new/full request
2021-03-06 17:54:08 ERROR (MainThread) [homeassistant.components.hassio] Failed to to call /snapshots/new/full -