I'm an developer and a fans of Apple, writing because you handled a forum thread that exactly matches an issue I can still reproduce today: "VPN causes CarPlay to not work" (developer.apple.com/forums/thread/712441), filed as FB11285432 back in August 2022.
Summary: When any Packet Tunnel VPN with includeAllNetworks enabled is active, wired CarPlay fails to establish a connection. The phone charges normally, but the head unit never detects CarPlay.
Steps to reproduce (iPhone on iOS [iOS 26.5.2], [Volkswagen's universal in-vehicle infotainment system for the 2023 and 2024 model years] head unit, USB-C wired CarPlay):
- Start a VPN configured with includeAllNetworks = true (reproduced with Shadowrocket; other users report the same with ExpressVPN, Google One VPN, etc.)
- Plug in the USB cable
- Result: CarPlay never connects. Charging works.
Additional observations:
- With the VPN off, the same phone/cable/car connects instantly, ruling out hardware.
- If CarPlay is established first and the VPN is enabled afterward, the existing session keeps working — only the initial handshake/discovery is blocked.
- Consistent with thread 712441, excluding local networks does not help.
This suggests includeAllNetworks blocks the mDNS/discovery traffic on the USB virtual Ethernet interface that CarPlay needs, with no exemption available.
Two questions:
- Is there any supported configuration that allows includeAllNetworks and first-time CarPlay connection to coexist?
- If not, is FB11285432 still tracked? I'd be happy to file a new Feedback report referencing it with current repro details if that helps prioritization.
Thanks for your time — your forum posts on Network Extension have been invaluable in diagnosing this.