I have been struggling for a while to get Thunderbird to synching properly with the ecloud contacts. At the end I found out that it was dead simple. The standard Thunderbird Addressbook works perfectly fine.
However the trick was to copy the right URL into the field “location” during setup. In the above and also in other posts it is suggested to copy the complete URL from the ecloud/contacts page into the setup dialog. However I had to strip some parts of the end of the URL. In my case I had to paste just the base URL part “https://murena.io/remote.php/dav” into the Addressbook setup wizzard.
this together with the right username (xxx@e.email) and password made it work at the end.
Hope it will help others to hear the default address book works fine. I didn’t try it but I guess the same approach would work for cardbook too.
The advice from the last 2 postings by @ewblen (syncing Contacts with CardBook) and @cliffi30 (syncing Calendar with native Tbird CalDAV calendar management) has also worked for me to sync both Contacts and Calendar on Thunderbird.
In fact this is saving my workflow since the UI for both of these Tbird integrations is far more useful than what’s currently available via the web UI on murena.io.