Sky Broadband UK have started to deploy MAP-T (RFC7599) with their new Sky Hub Max router.
Mapping of Address and Port using Translation (MAP-T) allows IPv4 traffic to be carried over a IPv6 only network.
They are also sharing IPv4 addresses between customers but it looks like adding DMZ settings gives you a 1:1 mapping.
Sky Broadband starting to share IPv4 addresses between users
I've been with Sky Broadband for a while, recently re-contracted (on FTTP) and was sent a new Sky Hub Max router (which I didn't need, but I've swapped it over from the old Sky router anyway). As expected, got a change of WAN IP, so updated my ping monitor over at thinkbroadband and was...