I can confirm a similar issue using the newest Buster minimal image (Armbian_19.11.7_Odroidxu4_buster_current_5.4.3_minimal) on the HC2. I am able to boot into a freshly written image, but cannot reboot successfully. When running `reboot now` or rebooting when prompted by `armbian-config` selections I hear the installed HDD spin down, see the heartbeat LED go solid, then start blinking as if a reboot happened -- but the system doesn't seem to come back up. The attached HDD never spins back up and I cannot connect via SSH until I pull the power and replug. After needing to manually replug twice (I have tested this a few times now) the HC2 fails to boot altogether with a solid blue heartbeat LED. I have both the HC1 and HC2, but I won't have access to my HC1 until tonight. I would be happy to provide any logs or try to troubleshoot with some direction.
