Hi Apple Network Team,
Good day. Recently we are experiencing some issues that when iOS or iPad OS connected to a Wi-Fi with captive portal, iOS sometimes failed to launch the full captive portal website. Based on TCPDump and WLAN dump logs, when this failure happened, we only see web client on iOS queried AAAA and HTTPS DNS queries without A query. Not all the websites are supporting and being hosted on both IPv4 and IPv6 servers. Is there a know bug on iOS and iPad OS side including OS version >= 36.2.