After updating to iOS 11, I've noticed iBooks automatically deleting epub files on iCloud Drive any time the device reboots. Even more to my annoyance is that since the update, I have unable to download my files over cellular data considering the books are only 1.3 MB. Books bought from the store seem to download however epubs added to iBooks and synced using iCloud do not download unless the device is on wifi. Alternatively, directly side loading the file to the device does not work for some odd reason (in previous version this work regardless of status). Airdropping the file shows completion yet I am unable to view the file. Any help on this matter will be appreciated.
Device is iPhone 6 on iOS 11.0.1
Device is iPhone 6 on iOS 11.0.1