@protonvpn forgot to mention, awesome work discovering and reporting this!
@protonvpn hmm, apparently this is already known and documented by OpenVPN:
“Many Apple services such as Push Notifications and FaceTime are never routed through the VPN tunnel, as per Apple policy.”
Found in this bird site thread: https://nitter.snopyta.org/BucciaBuccia/status/1243292224827383814
Personal instance of nitrohorse (nitrohorse.com).