We are facing the same issue with our game.It appears that Apple reviewers test apps behind a VPN. And this VPN is blocking some ports and not forwarding all traffic.We didn't find a solution yet. But we will try to submit another version using common ports (80, 443)

Is there a particular reason that UDP traffic is blocked on the network used for reviewing? It's because of the VPN they're using during the review. I don't know if it's a bug from their part or if it's intentional.

Hi, did someone find a solution ?

Hello @Jteam , Unfortunately we didn't find a solution. But we noticed in the past months that many developers are facing the same issue (UDP socket don't go through their VPN, while TCP does) So there is definitely something wrong on Apple reviewer's side. source : https://developer.apple.com/forums/thread/650612 https://developer.apple.com/forums/thread/133980 https://developer.apple.com/forums/thread/132096 https://developer.apple.com/forums/thread/131961 https://developer.apple.com/forums/thread/131152 https://developer.apple.com/forums/thread/130624 https://developer.apple.com/forums/thread/651264

Hello Jteam, we are facing the same issue - https://developer.apple.com/forums/thread/133938. Any news on this ? There are 20+ other people reporting this issue on the forum for the past 3 months. But still no one knows why Apple Reviewer can't block UDP packets (TCP seems to work fine). Maybe since the lockdown, their reviewers are doing the test at home from a VPN blocking UDP packets for some reason ?

So this issue is not fixed yet ? (it started 3 month ago) It boggles my mind how mods on this forum are just ignoring this issue even if there are suddenly a dozen of post reporting that Apple reviewers can't receive UDP packet since a few months ? What's going on ? This must be a Bug, how UDP protocol can be blocked ? Is this a new Apple standard or something ? So for the rest of us who can't use TCP fallback or don't have friends working at Apple, we are stuck forever at the review process. Great

I also tried to contact them but they didn't answer. The only workaround is to use TCP instead... This issue can lead to malicious behavior and can be used as an exploit. But it feels like until a press article talk about this issue, Apple won't even consider looking at this.

I couldn't edit my main post, so here is my last update on the subject. I fixed the issue I was facing by offering a TCP alternative to connect to my game servers. So the game will first try to connect in UDP and if it doesn't work, it will try to connect with TCP. The game has now been accepted by Apple reviewers, they can connect only with TCP for some reasons through their VPN. And since then thousand of users are successfully playing online (100% of them in UDP, no one connected on the TCP servers yet).