Last I checked there’s no good way to get detailed ‘why did I disconnect’ information from a VPN connection. For a provider-based VPN you could write the error information to disk in an App Group that you share between your provider and your app; that’s super ugly, but it’ll work.
Please do file an enhancement request requesting better support for this, then post your bug number, just for the record.
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Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware
let myEmail = "eskimo" + "1" + "@apple.com"
Thanks for the answer. I filed 29375097.