Can't sync with contacts iOS or macOS

Nextcloud version 11.0.1:
Operating system and version Debian 8:
Apache or nginx version Apache 2:
PHP version 5.6:

Hey ppl,

i just installed a fresh version of nextcloud. now im trying to set up syncing my Contacts via CardDAV on iOS and macOS but after a short loading time i get the message “cannot verfiy account name oder password” even though it is correct. I can log in using the same credentials in the browser. the nextcloud file sync app is also up and running smooth. but the carddav feature seems to have problems

I’m using this URL: https://mydomain.com/remote.php/dav/addressbooks/users/myusername/

So far i don’t get any error messages in my apache Log.

edit:
When i open the URL in my Browser it says “This is the WebDAV interface. It can only be accessed by WebDAV clients such as the ownCloud desktop sync client.” So everything seems to be fine and listening but i just doesn’t verify. I tried using connections with SSL and without

Please try following address: https://mydomain.com/remote.php/dav/principals/users/myusername/ . The URL has changed with NC 11. This address works for me with MacOS and iOS.

Cheers,
Jürgen

I had a similar issue and was able to solve it by following the instructions in the official nextcloud admin manual refering to this issue.

Same here, after a long jurney to find a solution it is working now fine with mac (El Capitan and Sierra) with Nextcloud 12.0.3.3.
hostname: https://mydomain.com
path: /nextcloud/remote.php/dav/principals/users/myusername
(running nextcloud hosted and installed in the subdirectory of the webservice)

Thank you a lot for this great hint!!!
klaus