Given the details are undocumented "feature" of VPN/networking (but shared by an engineer in a 1:1 lab at WWDC24) I'm not including details here. That said, it seems surprising that VPNs can suddenly disconnect overnight with no warning.
Can this bug fix be prioritized during the iOS 27 cycle?
Our recommendation would be VPN onDemand to solve your use case.
Thanks. We are indeed using onDemand rules to get around this. It still has side effects (see below), and I still think this is something that should ultimately be solved on the iOS side.
Side effect: Users are unable to turn off the VPN from Control Center's stock VPN toggle or the system Settings app, as the onDemand rule causes the VPN to turn itself back on as soon as a network request is made. (We do have our own Control Center Widget to partially help, though.) We've gotten some user feedback - especially when trying to access captive portal screens on airplanes, for example - that they're unable to turn off the VPN from the system settings and end up fully uninstalling the network extension, and that's just a bad user journey.
