happy eyeballs for Web protection
As of right now, the Sophos XGs web Protection feature does not implement happy eyeballs which renders it unusable for IPv6 Endpoints - the only way to "fix" this is to simply force all http(s) traffic to use ipv4 instead.
It would be nice to see real dual stack support by implementing Happy Eyeballs.
AdminRich Baldry (Senior Product Manager, Network Security Group, Sophos Features & Ideas Laboratory) commented
In Version 18 our DPI-based web filtering will not interfere with the browser's implementation of happy eyeballs functionality.