Our App got rejected multiple times because the Apple reviewer was not able to connect to our Server. During the review our server received Data correctly but the ip that was trying to connect (a correct NAT64 translated IPv4 Address), was not reachable when the server tried to send data back. We did everything we could to reproduce the issue, but no matter what we tried (IPv4 only, IPv6 only, NAT64, VPN and different locations around the world) the server was always reachable and always responded correctly). The only solution we can think of, is that a firewall on Apples side prevents UDP traffic to reach the reviewer. Has anyone else an idea of what could go wrong?