NC does not accept local directories as external storage

I am using Nextcloud 27.1.5 with nginx on a raspbery pi 5
Nextcloud in installed in /var/www/nextcloud
/var/CloudData is the data-directory for nextcloud

I want to use a local Directory (/home/NN/CloudLocal ) as local storage.
The directory has the correct rights (www-data:www-data)
But Nextcloud refuses to accept that directory as external storage.

The only way to make a local directory acceptable for Nextcloud is
to place it in the directory /var/

Under Nextcloud 27 on a Pi 4 there where no problems.

What is going wrong?

My config.php:

<?php $CONFIG = array ( 'instanceid' => 'xxxx', 'passwordsalt' => 'xyxyxyxy', 'secret' => 'zzzzzzz', 'trusted_domains' => array ( 0 => 'nnn.io', ), 'datadirectory' => '/var/CloudData', 'dbtype' => 'pgsql', 'version' => '27.1.5.1', 'overwrite.cli.url' => 'https://pgwl-os.dedyn.io', 'dbname' => 'nextcloud', 'dbhost' => 'localhost', 'dbport' => '', 'dbtableprefix' => 'oc_', 'dbuser' => 'nextcloud', 'dbpassword' => '2Wuu5E3JtErQ', 'installed' => true, 'memcache.local' => '\\OC\\Memcache\\APCu', 'memcache.locking' => '\\OC\\Memcache\\Redis', 'redis' => array ( 'host' => '/var/run/redis/redis-server.sock', 'port' => 0, 'timeout' => 0.0, ), 'maintenance' => false, 'updater.release.channel' => 'stable', 'default_phone_region' => 'DE', 'mail_smtpmode' => 'smtp', 'mail_smtpsecure' => 'ssl', 'mail_sendmailmode' => 'smtp', 'mail_from_address' => 'paul', 'mail_domain' => 'berbers.de', 'mail_smtpauthtype' => 'LOGIN', 'mail_smtpauth' => 1, 'mail_smtphost' => 'mail.manitu.de', 'mail_smtpport' => '465', 'mail_smtpname' => 'u20374@berbers.de', 'mail_smtppassword' => 'ZDMPVv9d2874', 'theme' => '', 'logtimezone' => 'Europe/Berlin', 'loglevel' => 2, 'filelocking.enabled' => true, 'auth.bruteforce.protection.enabled' => false, 'data-fingerprint' => '578c48d9c1ed24abbc8bef96c6db637e', 'enable_previews' => true, 'enabledPreviewProviders' => array ( 0 => 'OC\\Preview\\PNG', 1 => 'OC\\Preview\\JPEG', 2 => 'OC\\Preview\\GIF', 3 => 'OC\\Preview\\HEIC', 4 => 'OC\\Preview\\BMP', 5 => 'OC\\Preview\\XBitmap', 6 => 'OC\\Preview\\MP3', 7 => 'OC\\Preview\\TXT', 8 => 'OC\\Preview\\MarkDown', 9 => 'OC\\Preview\\Movie', 10 => 'OC\\Preview\\MKV', 11 => 'OC\\Preview\\MP4', 12 => 'OC\\Preview\\AVI', 13 => 'OC\\Preview\\PDF', ), );

How precision does it refuse to accept it? What are the messages or indications?

The only way to make a local directory acceptable for Nextcloud is
to place it in the directory /var/

What are the permissions of the parent folder (/home/NN)?