Going from Supervised to Home Assistant OS - restoring a full backup the SSD won't boot

I’'ve been scratching my head over this for the entire day, so let me see if the community can shed some light …

Context:

  1. I’m running on a Raspberry Pi 3, and in the process of migrating away from a Supervised install running on an SSD to a Home Assistant Operating System install

  2. I have a full backup (via the Google Drive Backup addon) of my system

  3. My system still has an SD card with just ‘bootcode.bin’ and an empty ‘timeout’ file on it, or else it won’t boot from the SSD

  4. I’ve flashed the image to the SSD, plugged it in and powered up, everything went well, HA starts up ok

  5. If I go to the console on the Pi and type “core restart”, the Pi will reboot ok just file. I can shutdown and power-cycle it and it comes back ok as well

  6. After the initialization is complete, I go to the web interface and select “restore” instead of creating a user. Select my backup file and perform a “full restore”

  7. After the restore is complete, eventually HA is back exactly as it was when the backup was taken, including all configuration, dashboards, addons, historical data, etc.

  8. At this point if I restart the host or powercycle it, it will not come back again, I see an error on the HDMI console bus [email protected]: usb dr_mode not found, plus some entries saying that no boot device was found on the USB bus.

Question: is there a way to restore a full backup from a different installation type (in this case it was Supervised running on Raspbian) onto a different installation type - I want to restore on a system running Home Assistant Operating System?

best regards!
Claudio