I had restored from 7.450, and everything worked fine. Then, I restored from 7.402 and experienced some anomalies. I wanted to try another restore to test something.
I did a factory reset, and then power-cycled the ASG220 with a 7.402 backup file on USB. I tried twice and have been unable to reach the ASG on either the internal or external IP.
I just power-cycled again with a 7.450 backup in place. I still can't get through.
I removed the USB and power-cycled just to get a restart. Still can't get through.
I have opted for a re-install from ISO. I waited until the CD was ejected and the message "Intallation finsihed" appeard on the LCD of the ASG220. I powered down, inserted a USB stick with the same 7.402 backup I restored into 7.450 and powered back up. Works fine now.
Cheers - Bob
PS I still wonder if this wasn't caused by NOT rebooting after the initial restore. I'm definitely doing that now! See https://community.sophos.com/products/unified-threat-management/astaroorg/f/98/t/67884