Sync contacts, Calendar over DavDroid - NC 12

I want syncronize Calendar, Contacts between android 7 phone and NC12 via
DAVdroid. 1.6.2
Connection between phone and NC12 looks fine, but contact and calendar not be synchronized…:frowning:

What i have to do?

Im not linux or Web expert, im using NC12 over easy deployment/ Webmin

anything else works fine…

It’s a bug of Android. I suppose you use nginx for serving NextCloud.

Change ssl_ecdh_curve in your nginx config to prime256v1;.

This bug is fixed in Android 7.1.
You’ll find further informations at