Plug it into a monitor or TV and keep an eye on the console.

I have an older NUC that will not cooperate with certain brands of NVMe drive under PVE…the issue sounds like yours where it would work for an arbitrary amount of time before crashing the file system, attempting to remount read-only and rendering the system inert and unable to handle changes like plugging a monitor in later, yet it would still be “on”.

I recommend Dockge over Portainer if you want a web admin panel. https://github.com/louislam/dockge

It’s basically docker compose in a website, and you can just decide one day to turn it off and use the compose files directly. No proprietary databases or other weirdness.