IPv6 issue on iOS

Question

The IPv6 addresses returned in the code below don't match the IPv6 addresses found in Settings. The first half of the IP's matches, but the second half is always different. Is this expected? Am I doing something wrong in the code below?

IP address in Settings: "2601:483:4500:4d92:1cc9:84c9:7a3a:5101"

IP address in app: "2601:483:4500:4d92:f014:24c0:100::"

static func getWiFiAddress() -> String? {
    var address : String?

    // Get list of all interfaces on the local machine:
    var ifaddr : UnsafeMutablePointer<ifaddrs>?
    guard getifaddrs(&ifaddr) == 0 else { return nil }
    guard let firstAddr = ifaddr else { return nil }

    // For each interface ...
    for ifptr in sequence(first: firstAddr, next: { $0.pointee.ifa_next }) {
        let interface = ifptr.pointee

        // Check for IPv4 or IPv6 interface:
        let addrFamily = interface.ifa_addr.pointee.sa_family
        if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {

            // Check interface name:
            let name = String(cString: interface.ifa_name)
            if  name == "en0" {

                // Convert interface address to a human readable string:
                var addr = interface.ifa_addr.pointee
                var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
                getnameinfo(&addr, socklen_t(interface.ifa_addr.pointee.sa_len),
                            &hostname, socklen_t(hostname.count),
                            nil, socklen_t(0), NI_NUMERICHOST)
                address = String(cString: hostname)
            }
        }
    }
    freeifaddrs(ifaddr)

    return address
}

Thanks in advance!