hassOS - RPi keeps rebooting

So my home assistant was running happily for like a year on a random Sandisk Ultra card.
Then I decided to back up the card and move it to a better one - somehow corrupted it in the process - had to start again.

So that was around a month ago. I bought a Sandisk Max Endurance card, installed everything from scratch as I didn’t believe in backups.

Now today hass is down and when I plugged the RPi to my monitor it seems that it keeps rebooting.
It get’s to around HassOS Configuration Manager and restarts, sometimes sooner sometimes later but always goes past Network Manager Script Dispatcher Service.

I have 3 ideas:

  • Power - could be a problem, but I tried different cable and if I take the SD card out it stays on without issues so that shouldn’t be it
  • SD card - yeah that’s my strongest guess, but as I mentioned I just bought this card and bought the Max Endurance one which is rated for 3 years of constant video capture…
  • OS? - corrupted files but not the card? not sure

Any ideas on how to diagnose/troubleshoot?

Look at the logs.

Fair enough. Now I hate asking, but I did some googling and am confused as to where I should be looking.
Going through the SD card I can immediately see logs folder on hassos-data, but these are journal files… is this what I’m looking for or am I in the wrong place?

Again, apologies for my ignorance but so far it worked quasi-fine and I didn’t need to look at folder structure on the card.

The log information is stored in the configuration directory as home-assistant.log

Yeah… there’s nothing there:

2020-12-02 08:06:19 WARNING (MainThread) [homeassistant.loader] You are using a custom integration for 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.
2020-12-02 08:06:32 WARNING (MainThread) [homeassistant.setup] Setup of recorder is taking over 10 seconds.
2020-12-02 08:07:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder
2020-12-02 08:08:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder
2020-12-02 08:09:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder
2020-12-02 08:10:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder
2020-12-02 08:11:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder
2020-12-02 08:12:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder
2020-12-02 08:13:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder
2020-12-02 08:14:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder
2020-12-02 08:15:20 WARNING (MainThread) [homeassistant.bootstrap] Waiting on integrations to complete setup: recorder

I’m even more confused now.
I tried again and it booted but couldn’t access the frontend.
I took a new card, put the hassOS on it. Boots fine. Restored snapshot from a month ago and can’t access the frontend now.
Logs are exactly the same so completely nothing interesting