Experiencing the same issue in my app after upgrading to Xcode 16. When running the app from Xcode the data does not persist.
Launching the app from the device everything seems to work fine, data changes are persisted across launches.
The only log I see when running from Xcode is "CoreSVG has logged an error. Set environment variabe "CORESVG_VERBOSE" to learn more.".
Everything was working fine in Xcode 15.