If it shows that address while connected to WWAN only, then it's probably coming from 464xlat -- basically your phone synthesizing its own internal v4 network, with any outbound v4 connections being translated into v6 connections to 64:ff9b::/96 (or whatever your ISP's NAT64 range is).

464xlat works well for letting legacy v4-only programs access v4 via NAT64, but it doesn't help them reach native v6 hosts.

That 192.168.0.X address in an IPv4 private address. I'm assuming your phone is connected to Wi-Fi.

I specifically turned off Wi-Fi for the test. Although it is possible that the phone kept it as an ip address. I don't have a way to find out.