I installed davdroid from the f-droid repository. I configured the connection to my ownCloud to sync contacts, calendars and tasks. All syncs are fine but the contacts sync.
When I look in the Android contacts app I can see that my contacts are being synced. New contacts were added to the app. But at some point the synced contacts disappear. After the syncing process the contact app shows only four contacts. I figured out, that there is something special about these for contacts. All four have in common that I added them on my iPhone and synced them to my ownCloud.
But I have no idea why all the other contacts aren’t shown after the sync finished.
Here are some information about my system:
Tablet: Nexus 7 (Edition 2012)
Android Version: 5.1.1
Build Number: LMY47V
You could find the log at this link.