At some occasions (especially when booting and after app updates), Android looks for orphaned accounts which are not associated to a sync adapter. Unfortunately, this check is sometimes run before DAVdroid is available. So, Android doesn't find DAVdroid, thinks that all your DAVdroid accounts are orphaned and deletes them. This problem is known for two cases:
- when DAVdroid has been moved to the SD card / USB storage (although this is forbidden by the app manifest),
- because of a Google Play bug which may affect users who have got DAVdroid via Play Store on
- some Android 4.1 devices,
- many Android 4.4.x devices, regardless of the manufacturer, for instance LG G3 (LG-D855) with Android 4.4.2,
- and some other devices.
- DAVdroid must not be moved to external storage (SD card / USB storage).
- Upgrade your device to the latest available Android version (if your firmware is really old, you may consider a custom ROM).
- If you use Google Play, install the DAVdroid JB Workaround (only available on Android 4.x).
- You may consider to install DAVdroid from another source (e.g. F-Droid).