I’m not aware of any known issue that matches these symptoms. As you’ve noted, iOS is expected to preserve app group containers across OS and app installs. This certainly works for most apps and most users, but that doesn’t preclude there being a bug that causes this problem for some users of some apps. To investigate this we need to see a sysdiagnose log taken immediately after the user notices the problem. That’s gonna be tricky to acquire given that this problem isn’t obviously reproducible. I have a bunch of background on this in Using a Sysdiagnose Log to Debug a Hard-to-Reproduce Problem. Key to that process is the ability to quickly and reliably identify that the problem has occurred. If I were in your shoes I’d add specific code for that, code that’s not tied to UserDefaults or Core Data. Both of those are big, complex subsystems, which makes it hard to know whether you’re hitting a problem with that subsystem or something more fundamental. Rather, I recommend that you store this state in fil
Topic:
App & System Services
SubTopic:
Core OS
Tags: