Migrated VPN Service Broken with Catalina
My Mac mini has been working just fine with macOS Mojave as a VPN server following the migration method described in https://developer.apple.com/support/downloads/macOS-Server-Service-Migration-Guide.pdf , but after upgrading to macOS Catalina there is trouble:
The VPN clients connect just fine on the internal network, but not on an external network; which makes the VPN server a bit pointless! I can confirm that all was working well with the server running macOS Mojave, and my iOS 13 and iPadOS 13 clients have been connecting just fine; it is the upgrade to macOS Catalina on the server that has caused this problem.
Here are the log entries for a failed connection: