I don't know is here for Unity Games but we sending our game to review.
We tried all things like low battery mode, slow connection mode with iPhone11 IOS 13.3.1 and all works well.
After apple staff trying to connect our server peer connected but timeout in 5 sec. And at client side socket connection failed.
Same os same device works well at our side additionally, iPhone 7, İphone 8+ etc works, too. PC, Android versions works, too.
What can we do at this stage?