jagged flame
I've always had trouble with both of my Yellows when rebooting, typically after a HAOS update. I've finally narrowed it down.
I use an NVMe drive for data. When the device is stuck, sshing into port 22222, one can see it stuck before starting HA doing a docker ps, but without the NVMe data volume mounted. All soft reboots (e.g. "reboot" from ssh) stay in this state where the NVMe device is not seen by the OS and does not appear in /dev.
A hard reboot (pulling out the PoE cable in my case) instantly solves the problem.