I had a weird problem with access rights. I could read/write objects within collections (that where already synced in DavX), but could not read/write the collections themselves. Setting rights - type to "owner_only" did not help.
Log messages:
[INFO] Successful login: 'user@example.de
[INFO] Access to '/user@example.com/' denied for 'user@example.com'
Access to the requested resource forbidden.
What helped was updating the "rights" file so it says permissions: RWrw. So maybe the documentation could or should be updated to reflect this?