Thanks David it worked see my comment below
After my HA died randomly this morning, I’ve replaced the SD card and tried this new restore function after flashing the latest version. After selecting my backup file, the page goes straight back to the initial configuration (define username etc) as if nothing happened. Then the page stops responding, and the PI doesn’t do anything. After waiting 20 minutes I tried again with a partial restore and same problem. It does respond to pings but thats about it. Any ideas?