How to troubleshoot HAOS?

Hello Everyone,

I need help on how can I troubleshoot my HAOS installation (KVM). Yesterday evenening everything was fine. Today I can’t connect to the web interface. From the Host OS everything looks fine - the VM starts without errors. Also the HAOS looks like it’s starting fine - It spits out the IP adresses after waiting for supervisor to startup. But I can’t connect to it either by local IP or by Nabu Casa external access. Chrome gives me “ERR_EMPTY_RESPONSE” and that is it. How can I get access to logs etc on the ha command line ? I’d like to get this working again, and it would be great to know what happened overnight that killed it.
EDIT: Note: I can ping both the host and the HAOS vm and they reply, so the network is running properly on both.
EDIT2: I see that at least one of my automations works (physical light switch is turning on light via Node-RED and HA entity)
I’m on OS v6.6 and Core 2021.11.3.

Thank you for any help in advance.

EDIT3: This is my homeassistant.log:

2021-11-13 12:20:32 WARNING (SyncWorker_0) [homeassistant.loader] We found a custom integration nodered which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:32 WARNING (SyncWorker_1) [homeassistant.loader] We found a custom integration favicon which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:32 WARNING (SyncWorker_0) [homeassistant.loader] We found a custom integration ytube_music_player which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:32 WARNING (SyncWorker_0) [homeassistant.loader] We found a custom integration hacs which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:32 WARNING (SyncWorker_1) [homeassistant.loader] We found a custom integration smartthinq_sensors which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:32 WARNING (SyncWorker_3) [homeassistant.loader] We found a custom integration bureau_of_meteorology which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:32 WARNING (SyncWorker_4) [homeassistant.loader] We found a custom integration skodaconnect which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:32 WARNING (SyncWorker_2) [homeassistant.loader] We found a custom integration govee which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:32 WARNING (SyncWorker_0) [homeassistant.loader] We found a custom integration google_geocode which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-11-13 12:20:33 WARNING (Recorder) [homeassistant.components.recorder.util] Ended unfinished session (id=162 from 2021-11-13 10:43:39)
2021-11-13 12:20:40 WARNING (SyncWorker_9) [homeassistant.components.influxdb.sensor] Query returned no results, sensor state set to UNKNOWN: select mean(diskBytes) as value from "monitor"."shard" where time > now() - 1m AND "database"='xxx'.
2021-11-13 12:20:40 WARNING (MainThread) [homeassistant.helpers.template] Template warning: 'float' got invalid input 'unknown' when rendering template '{{ (value | float / 1024 /1024) | round(1) }}' but no default was specified. Currently 'float' will return '0', however this template will fail to render in Home Assistant core 2022.1
2021-11-13 12:20:41 WARNING (MainThread) [androidtv.adb_manager.adb_manager_async] Couldn't connect to 192.168.1.16:5555.  TcpTimeoutException: Connecting to 192.168.1.16:5555 timed out (1.0 seconds)
2021-11-13 12:20:41 WARNING (MainThread) [homeassistant.components.androidtv.media_player] Could not connect to K_MiTVBOX at 192.168.1.16:5555 using Python ADB implementation with adbkey='/config/.storage/androidtv_adbkey'
2021-11-13 12:20:41 WARNING (MainThread) [androidtv.adb_manager.adb_manager_async] Couldn't connect to 192.168.1.15:5555.  TcpTimeoutException: Connecting to 192.168.1.15:5555 timed out (1.0 seconds)
2021-11-13 12:20:41 WARNING (MainThread) [homeassistant.components.androidtv.media_player] Could not connect to DP_MiTVBOX at 192.168.1.15:5555 using Python ADB implementation with adbkey='/config/.storage/androidtv_adbkey'
2021-11-13 12:20:41 WARNING (MainThread) [androidtv.adb_manager.adb_manager_async] Couldn't connect to 192.168.1.17:5555.  TcpTimeoutException: Connecting to 192.168.1.17:5555 timed out (1.0 seconds)
2021-11-13 12:20:41 WARNING (MainThread) [homeassistant.components.androidtv.media_player] Could not connect to MP_MiTVBOX at 192.168.1.17:5555 using Python ADB implementation with adbkey='/config/.storage/androidtv_adbkey'
2021-11-13 12:20:41 WARNING (MainThread) [homeassistant.components.media_player] Platform androidtv not ready yet: None; Retrying in background in 30 seconds
2021-11-13 12:20:41 WARNING (MainThread) [homeassistant.components.media_player] Platform androidtv not ready yet: None; Retrying in background in 30 seconds
2021-11-13 12:20:41 WARNING (MainThread) [homeassistant.components.media_player] Platform androidtv not ready yet: None; Retrying in background in 30 seconds
2021-11-13 12:20:41 WARNING (MainThread) [custom_components.govee] API is back online.
2021-11-13 12:20:41 WARNING (MainThread) [homeassistant.config_entries] Config entry 'MP_MiTVBOX' for nfandroidtv integration not ready yet: Failed to connect; Retrying in background
2021-11-13 12:20:41 WARNING (MainThread) [homeassistant.config_entries] Config entry 'K_MiTVBOX' for nfandroidtv integration not ready yet: Failed to connect; Retrying in background
2021-11-13 12:20:43 WARNING (MainThread) [homeassistant.config_entries] Config entry 'MP_MiTVBOX' for nfandroidtv integration not ready yet: Failed to connect; Retrying in background
2021-11-13 12:20:44 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.214 @ 192.168.1.214: Error connecting to ('192.168.1.214', 6053): [Errno 113] Connect call failed ('192.168.1.214', 6053)
2021-11-13 12:20:44 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.213 @ 192.168.1.213: Error connecting to ('192.168.1.213', 6053): [Errno 113] Connect call failed ('192.168.1.213', 6053)
2021-11-13 12:20:44 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.203 @ 192.168.1.203: Error connecting to ('192.168.1.203', 6053): [Errno 113] Connect call failed ('192.168.1.203', 6053)
2021-11-13 12:20:45 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.253 @ 192.168.1.253: Error connecting to ('192.168.1.253', 6053): [Errno 113] Connect call failed ('192.168.1.253', 6053)
2021-11-13 12:20:45 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.207 @ 192.168.1.207: Error connecting to ('192.168.1.207', 6053): [Errno 113] Connect call failed ('192.168.1.207', 6053)
2021-11-13 12:20:45 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.209 @ 192.168.1.209: Error connecting to ('192.168.1.209', 6053): [Errno 113] Connect call failed ('192.168.1.209', 6053)
2021-11-13 12:20:45 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.210 @ 192.168.1.210: Error connecting to ('192.168.1.210', 6053): [Errno 113] Connect call failed ('192.168.1.210', 6053)
2021-11-13 12:20:45 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.211 @ 192.168.1.211: Error connecting to ('192.168.1.211', 6053): [Errno 113] Connect call failed ('192.168.1.211', 6053)
2021-11-13 12:20:45 WARNING (MainThread) [aioesphomeapi.reconnect_logic] Can't connect to ESPHome API for 192.168.1.215 @ 192.168.1.215: Error connecting to ('192.168.1.215', 6053): [Errno 113] Connect call failed ('192.168.1.215', 6053)
2021-11-13 12:20:49 WARNING (MainThread) [homeassistant.components.sensor] Setup of sensor platform onewire is taking over 10 seconds.
2021-11-13 12:20:51 ERROR (Thread-9) [pychromecast.socket_client] [Głośnik - Przedpokój(192.168.1.220):8009] Failed to connect to service ServiceInfo(type='mdns', data='Google-Nest-Mini-._googlecast._tcp.local.'), retrying in 5.0s
2021-11-13 12:20:54 ERROR (Thread-10) [pychromecast.socket_client] [Głośnik - Mały pokój(192.168.1.225):8009] Failed to connect to service ServiceInfo(type='mdns', data='Google-Home-Mini-._googlecast._tcp.local.'), retrying in 5.0s
2021-11-13 12:20:57 ERROR (Thread-11) [pychromecast.socket_client] [Głośniki Logitech(192.168.1.221):8009] Failed to connect to service ServiceInfo(type='mdns', data='Google-Home-Mini-googlecast._tcp.local.'), retrying in 5.0s
2021-11-13 12:21:00 ERROR (Thread-12) [pychromecast.socket_client] [Głośnik - Łazienka(192.168.1.224):8009] Failed to connect to service ServiceInfo(type='mdns', data='Nest-Audio-._googlecast._tcp.local.'), retrying in 5.0s
2021-11-13 12:21:00 WARNING (MainThread) [androidtv.adb_manager.adb_manager_async] Couldn't connect to 192.168.1.16:5555.  OSError: Connect call failed ('192.168.1.16', 5555)
2021-11-13 12:21:00 WARNING (MainThread) [homeassistant.components.androidtv.media_player] Could not connect to K_MiTVBOX at 192.168.1.16:5555 using Python ADB implementation with adbkey='/config/.storage/androidtv_adbkey'
2021-11-13 12:21:01 WARNING (MainThread) [androidtv.adb_manager.adb_manager_async] Couldn't connect to 192.168.1.15:5555.  TcpTimeoutException: Connecting to 192.168.1.15:5555 timed out (1.0 seconds)
2021-11-13 12:21:01 WARNING (MainThread) [homeassistant.components.androidtv.media_player] Could not connect to DP_MiTVBOX at 192.168.1.15:5555 using Python ADB implementation with adbkey='/config/.storage/androidtv_adbkey'
2021-11-13 12:21:01 WARNING (MainThread) [androidtv.adb_manager.adb_manager_async] Couldn't connect to 192.168.1.17:5555.  TcpTimeoutException: Connecting to 192.168.1.17:5555 timed out (1.0 seconds)
2021-11-13 12:21:01 WARNING (MainThread) [homeassistant.components.androidtv.media_player] Could not connect to MP_MiTVBOX at 192.168.1.17:5555 using Python ADB implementation with adbkey='/config/.storage/androidtv_adbkey'
2021-11-13 12:21:03 ERROR (Thread-14) [pychromecast.socket_client] [Mi TV BOX - Duzy pokoj(192.168.1.15):8009] Failed to connect to service ServiceInfo(type='mdns', data='MIBOX4-32fdf8256dc526372e5d3b63403f3f65._googlecast._tcp.local.'), retrying in 5.0s
2021-11-13 12:21:05 ERROR (MainThread) [custom_components.ytube_music_player.media_player] async_update_selects failed
2021-11-13 12:21:07 ERROR (Thread-15) [pychromecast.socket_client] [Mi TV BOX - Kuchnia(192.168.1.16):8009] Failed to connect to service ServiceInfo(type='mdns', data='MIBOX4-e22e77a425c64d6f1eec753f9210c963._googlecast._tcp.local.'), retrying in 5.0s
2021-11-13 12:22:02 WARNING (MainThread) [androidtv.adb_manager.adb_manager_async] Couldn't connect to 192.168.1.15:5555.  TcpTimeoutException: Connecting to 192.168.1.15:5555 timed out (1.0 seconds)
2021-11-13 12:22:02 WARNING (MainThread) [homeassistant.components.androidtv.media_player] Could not connect to DP_MiTVBOX at 192.168.1.15:5555 using Python ADB implementation with adbkey='/config/.storage/androidtv_adbkey'
2021-11-13 12:22:02 WARNING (MainThread) [androidtv.adb_manager.adb_manager_async] Couldn't connect to 192.168.1.17:5555.  TcpTimeoutException: Connecting to 192.168.1.17:5555 timed out (1.0 seconds)
2021-11-13 12:22:02 WARNING (MainThread) [homeassistant.components.androidtv.media_player] Could not connect to MP_MiTVBOX at 192.168.1.17:5555 using Python ADB implementation with adbkey='/config/.storage/androidtv_adbkey'

and the weirdest thing - my wife has access via her account via the phone app.

I’m confused - there are no errors in any of the logs (at least I didn’t find anything), automations work, zigbee2mqtt devices work (I can see now via the wifes phone app).
Does anyone have any ideas what can I do next ?

Try clearing the cache in your browser or use a different browser? I find Chrome’s caching es[ecially annoying at times.

I think it’s something with my lets encrypt cert that got renewed by my router.
But that doesn’t explain why I can’t open the HA page on my laptop, my PC (and 2 Windows VMs, and 1 Linux VM I have on it), my HA phone app and even on the HAOS Host OS. And it doesn’t give me any errors anywhere - just doesn’t load. Doesn’t matter if I try to connect from inside or outside my network.
I can open it on my phones browser, my wifes HA phone app, my wifes tablet (chrome) etc.

EDIT: My HAOS Host+VM just got a reboot after cert overwrite and everything seems to be ok.

There should be some kind of error message about cert mismatch or something, and not just an empty response to the browser!!!