Hard drive filled up, now web page, sogo and nextcloud won't sign in

You can forget about slapd, it is for OpenLDAP account provider.
From the command outcome sssd and nsdc are running, and for httpd-admin you already found a fix.

To fix the account provider error there are others than will be able to provide better help, but you can try:

signal-event nethserver-sssd-update
signal-event nethserver-dc-update