That'd be an interesting take on Carrier-grade NAT. The approach I'm familiar gives phones a non-routable IPv4 address to get to the carrier's NAT gateway, but

That'd be an interesting take on Carrier-grade NAT. The approach I'm familiar gives phones a non-routable IPv4 address to get to the carrier's NAT gateway, but I can imagine shenanigans with some combination of 6to4, phone settings and/or DNS. Anyone seen such a setup in the wild? I'm interested in the errors OP saw.. was it just niche non-HTTP(S) access which broke, or all websites without an AAAA record?