This looks similar to your issue:
If it does now work maybe we find some hints in /var/lib/nethserver/nextcloud/nextcloud.log
or in the config:
cat /usr/share/nextcloud/config/config.php
config show nextcloud
This looks similar to your issue:
If it does now work maybe we find some hints in /var/lib/nethserver/nextcloud/nextcloud.log
or in the config:
cat /usr/share/nextcloud/config/config.php
config show nextcloud