No contacts / calender / notes

I can connect to my NC server on opensuse from my phone and exchange files.
on the phone I installed davdroid. apps for contacts, calender, notes ar enabled in NC.

  1. when selecting save contacts on the phone I receive a message that a file has been uploaded, but nothing can be found when connecting with a linux client.

  2. how do I sync a calender?

  3. when trying to connect to the server via Nextcloud SMS or Notes, it tells me that that account already exists on the phone. how can i save SMS and work with the notes?

did I miss someting?