Not sure if it's related or not. I'm running OMV on a rock64 SBC with 4gb ram.
I started noticing the issue today. For the short amount of time my board is online I noticed that portainer kept stopping. I quickly uninstalled it and then checked docker ps and docker stats both of which showing no containers running. Uninstalled docker and haven't had OMV be unreachable yet.
Will report back any findings.