I live in a rural area and depend on ATT's unlimited hotspot plan (that's now defunct) for my internet. It uses CG NAT and provides no IPv6 addresses.

However, you throw a SIM card from your phone in the hotspot and you'll magically have an IPv6 address, even without changing the APN. It's ridiculous that I have to resort to using a VPN to bypass all the troubles being behind a CG NAT entails.