We also have this issue exclusive to iOS 14. Our app uses a PacketTunnelProvider VPN extension. It essentially acts as a "local tunnel" to listen for DNS queries on the interface, block adult content, and write back the packets to the interface via UDP packets. Our app has worked fantastically until users updated to iOS 14. We are totally unable to find a solution to this issue and are starting to believe the issue may not with us but rather with iOS.

We also have had hundreds of customer complaints about total loss of networking while on our VPN - only for iOS 14. We use BSD Sockets in the packet tunnel provider for UDP - as a DNS proxy of sorts. Prior to iOS 14, everything works fine. As soon as users updated to 14, many have no networking whatsoever. We're finding that recv is never called. I've tried adding the local privacy permission to no avail. Do we need the multicast entitlement?