Apple made a change in iOS 17 that downgraded permissions to access your calendar from apps. This applies to both APDL and Logbook Pro for iOS. In iOS 17 the calendar permissions fell back to "ADD ONLY" where it was full access previously allowing the app to remove and create entries as needed. You will need to manually change the permission to FULL ACCESS (create, edit, delete entries) per the info below.
APDL needs FULL ACCESS in order to update calendar entries if you have Calendar Sync enabled in Settings > Calendar. If you don't make this change manually then calendar entries may be duplicated as we can't remove and replace them as your flights update. To make this change in APDL go to your device's Settings > Privacy & Security > Calendars > APDL and change to FULL ACCESS. We hope to address this in our upcoming major release for APDL.
Logbook Pro's calendar integration also requires FULL ACCESS in the event you want to delete a flight or make changes that may affect the associated calendar entry. Go to Settings > Privacy & Security > Calendars > Logbook Pro and change to FULL ACCESS.