I get pings averaging about 8 ms on 220.127.116.11; that's the same as the Vodafone DNS (which the Ultrahub tells me is 18.104.22.168), which suggests they're the same server, or if not, at the same location. That's not much more than the Ultrahub just across the house at 4 ms.
But with IPv6 it's a different story. Cloudflare's 2606:4700:4700::1111 gives an average of 131 ms, suggesting a trip to the US west coast. But to Vodafone's 2407:7000:2100:5300::1 it's 8 ms.
I wonder why? Is my ignorance showing? Any explanation appreciated.