Home assistant installation on RPI 4 with Argon 40 USB case

Hi All
I have run HA for a while as a virtual container in a NAS but now want to run it on it’s own machine. I bought an Argon 40 case and a m.2. drive to run it on. I have successfully installed Raspberry Pi OS on the m.2 USB drive and booted that no problem. When I write home assistant to the USB drive (in exactly the same way using Raspberry Pi Imager) it does not boot.
I’ve tried this several times now and once I managed to get to the webpage saying that HA is starting but the the restore from backup failed so I re-installed.
Now pings to the IP address do not work and the monitor that I have attached to the PI continually cycles between saying no signal and a blank screen.

Is there anything that I need to be aware of when booting HA from a USB drive?