I have below information when trying to register/activate the serial number:
"No internet connection. Check your internet connection as described in the product documentation."
While interface B has either static or DHCP assigned IP, and I can ping 8.8.8.8 from the console of the XG - so there is internet connection.
Initioally i have raised this issue in this topic:
https://community.sophos.com/products/xg-firewall/f/46/t/10794
This thread was automatically locked due to age.