Hmm - it’s a fairly reliable install method. I have installed and restored several times with no issues - this was on an Intel NUC though. Maybe something weird with that hardware - add “HP N40L microserver” to the title and you may get more specific answers.
Also - post the Supervisor logs for one of the installs…
side note… the CLI takes a VERY long time to get ready
so a reboot can without to much lying up to an hour before the web interface is ready
since i have a screen attached still i see the jump in to emergency mode a lot and ten i use login to guesstimate how far its from being ready, when i see the banner with ip info then i know its 20-30 mins from ready
when the cli is ready i then get system is not ready with state: setup error
its then i start to use the banner command to figure when its ready