It seemed to me, that I have a simmalary problem to https://help.nextcloud.com/t/nextcloud-macos-caldav-woes/34587
I tried, what is shown there as a solution - but I still am not able to connect.
I set up NC 15 on a testserver, using only a local IP and NO SSL,
So the OS X URL should be
http://192.168.0.148/nextcloud/remote.php/dav/principals/users/USERNAME/
I split the URL into 192.168.0.148 and /nextcloud/remote.php/dav/principals/users/USERNAME/ using Port 80.
At the apache log, I get
192.168.0.201 - - [10/Mar/2019:10:35:42 +0100] “PROPFIND /nextcloud/remote.php/dav/principals/users/USERNAME HTTP/1.1” 401 557 “-” “Mac+OS+X/1
0.13.6 (17G5019) CalendarAgent/399.2.2”
and nothing else.
I don’t have problems connecting to the calender by Browser.
And I can access the calender using the Outlook-Sync-Tool and sync it with my Outlook 2007 using Windows 7.
But I fail using OSX or IOS…