NextCloud 17.03 contacts does'nt sync to thunderbird (only)

Hi there ,
I’ve trying since one day to synchronize the “contacts” between Thunderbird and Nextcloud 17.03 (raspberrypi; Nextcloudpi). I put a new Nextcloud on a Raspberry (NextCloudpi). In parallel, a Nextcloud (15.0.13.1) also runs on a Raspberry, which I’ve set up “manually”. All the synchronization works very well here !!

Topic is now just my new Nextcloudpi

What is working now:

  1. All sync (calendar; contacts) between KDE (Suse Leap 15.1); Android <–> Nextcloudpi 17.03

What doesn’t work is the sync between Thunderbird and Nextcloud - error message with Thunderbird: Check https: //…/remote.php/.well-known/carddav.
Why get I this error message from Thunderbird?
Thunderbird settings - network.cookie.same-site.enabled -> false

Where’s the crucial configuration error? Where do I have to look? Does Thunderbird need a different setting on the Nextcloud? Which .htacces is for the config:
/var/www/nextcloud/config/.htaccess
/var/www/nextcloud/data/.htaccess
/var/www/nextcloud/.htaccess
/NextCloud/ncdata/.htaccess (NexCloud / ncdata is my datadir)

I hope for a tip from the NextCloud professionals - thanks

foggy


NextCloudPi version  v1.20.7
NextCloudPi image    NextCloudPi_07-21-19
distribution         Raspbian GNU/Linux 10 \n \l
automount            yes
USB devices          sda 
datadir              /NextCloud/ncdata
data in SD           no
data filesystem      ext2/ext3
data disk usage      404G/9,1T
rootfs usage         2,3G/57G
swapfile             /var/swap
dbdir                /var/lib/mysql
Nextcloud check      ok
Nextcloud version    17.0.3.1
HTTPD service        up
PHP service          up
MariaDB service      up
Redis service        up
Postfix service      up
internet check       ok
port check 80        closed
port check 443       closed
IP                   ***REMOVED SENSITIVE VALUE***
gateway              ***REMOVED SENSITIVE VALUE***
interface            wlan0
certificates         ***REMOVED SENSITIVE VALUE***
NAT loopback         no
uptime               3:11

Nextcloud configuration

{
    "system": {
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": {
            "8": "*.klara100.lan"
        },
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "17.0.3.1",
        "overwrite.cli.url": "https:\/\/nextcloud.klara100.lan",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "memcache.local": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0,
            "timeout": 0,
            "password": "***REMOVED SENSITIVE VALUE***"
        },
        "tempdirectory": "\/NextCloud\/ncdata\/tmp",
        "mail_smtpmode": "smtp",
        "mail_smtpauthtype": "LOGIN",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "preview_max_x": "2048",
        "preview_max_y": "2048",
        "jpeg_quality": "60",
        "overwriteprotocol": "https",
        "maintenance": false,
        "logfile": "\/var\/log\/nextcloud.log",
        "theme": "",
        "loglevel": "2",
        "log_type": "file",
        "mail_sendmailmode": "smtp",
        "trashbin_retention_obligation": "10, 15",
        "versions_retention_obligation": "auto, 20",
        "mail_smtpsecure": "ssl",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauth": 1,
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "465"
    }
}


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